Fixes: #5868

Context: dotnet/java-interop#821
Context: dotnet/java-interop@105d544

Originally, C# `interface`s couldn't contain non-"method" members,
nor did C# support interface default members.

Java did not have these restrictions:

	// Java; https://developer.android.com/reference/android/provider/CalendarContract.EventsColumns
	package android.provider;
	/* partial */ class CalendarContract {
	    protected static interface EventsColumns {
	        public static final int ACCESS_LEVEL = "accesslevel";
	    }
	}

Before C# 8, we bound these Java types by emitting a "proxy" class
which contained the constants (along with enumification):

	// C# binding
	namespace Android.Provider {
	    public partial class CalendarContract {
	        public abstract class EventsColumns {
	            public const string AccessLevel = (string) "accessLevel";
	        }
	    }
	}

With the introduction of C# 8, which allowed `interfaces` to contain
non-"method" members, along with interface default methods, we
did two things:

 1. We started emitting the constants into the interface declaration,
 2. We `[Obsolete]`d the "proxy" class, referring developers to use
    the interface type instead.

This resulted in:

	// C# Binding
	namespace Android.Provider {
	    public sealed partial class CalendarContract {
	        [Obsolete ("Use the 'Android.Provider.CalendarContract.IEventsColumns' type. This class will be removed in a future release.")]
	        public abstract partial class EventsColumns : Java.Lang.Object {
	            [Obsolete ("Use 'Android.Provider.CalendarContract.IEventsColumns.AccessLevel'. This class will be removed in a future release.")]
	            public const string AccessLevel = (string) "accessLevel";
	        }
	        protected internal partial interface IEventsColumns {
	            public const string AccessLevel = (string) "accessLevel";
	        }
	    }
	}

There was a minor problem with this, however: the semantics for
nested types with `protected` visibility differs between Java & C#:
Java allows
`android.provider.CalendarContract.EventsColumns.ACCESS_LEVEL` to be
accessed from anywhere.  C# *only* allows access to
`Android.Provider.CalendarContract.IEventDaysColumns.AccessLevel`
from subclasses of `CalendarContract`, and as `CalendarContract` is
`sealed`, it thus cannot be used from *anywhere*.

Fix this oversight by updating `src/Mono.Android/metadata` to change
the visibility of `android.provider.*Contract.*Columns` nested types
to be *public*.  This allows the constants to be used from everywhere:


	namespace Android.Provider {
	    public sealed partial class CalendarContract {
	        public partial interface IEventsColumns {
	            public const string AccessLevel = (string) "accessLevel";
	        }
	    }
	}

The following interface types are now `public`:

  * `Android.Provider.CalendarContract/IAttendeesColumns`
  * `Android.Provider.CalendarContract/ICalendarAlertsColumns`
  * `Android.Provider.CalendarContract/ICalendarCacheColumns`
  * `Android.Provider.CalendarContract/ICalendarColumns`
  * `Android.Provider.CalendarContract/ICalendarSyncColumns`
  * `Android.Provider.CalendarContract/IColorsColumns`
  * `Android.Provider.CalendarContract/IEventDaysColumns`
  * `Android.Provider.CalendarContract/IEventsColumns`
  * `Android.Provider.CalendarContract/IExtendedPropertiesColumns`
  * `Android.Provider.CalendarContract/IRemindersColumns`
  * `Android.Provider.CalendarContract/ISyncColumns`
  * `Android.Provider.ContactsContract/CommonDataKinds/ICommonColumns`
  * `Android.Provider.ContactsContract/IBaseSyncColumns`
  * `Android.Provider.ContactsContract/IContactNameColumns`
  * `Android.Provider.ContactsContract/IContactOptionsColumns`
  * `Android.Provider.ContactsContract/IContactStatusColumns`
  * `Android.Provider.ContactsContract/IDataColumns`
  * `Android.Provider.ContactsContract/IDataUsageStatColumns`
  * `Android.Provider.ContactsContract/IDeletedContactsColumns`
  * `Android.Provider.ContactsContract/IGroupsColumns`
  * `Android.Provider.ContactsContract/IPhoneLookupColumns`
  * `Android.Provider.ContactsContract/IPresenceColumns`
  * `Android.Provider.ContactsContract/IRawContactsColumns`
  * `Android.Provider.ContactsContract/ISettingsColumns`
  * `Android.Provider.ContactsContract/IStatusColumns`
  * `Android.Provider.ContactsContract/IStreamItemPhotosColumns`
  * `Android.Provider.ContactsContract/IStreamItemsColumns`
  * `Android.Provider.ContactsContract/ISyncColumns`

* Update dependencies from https://github.com/dotnet/installer build 20210502.3

Changes: dotnet/installer@0b60950...eceded1

Microsoft.Dotnet.Sdk.Internal
 From Version 6.0.100-preview.5.21229.1 -> To Version 6.0.100-preview.5.21252.3

Dependency coherency updates

Changes: dotnet/linker@bf37b29...307f6b0

Microsoft.NET.ILLink.Tasks
 From Version 6.0.100-preview.5.21227.1 -> To Version 6.0.100-preview.5.21229.1 (parent: Microsoft.Dotnet.Sdk.Internal

* Bump apkdiff, bump and sort apkdesc files

Co-authored-by: Peter Collins <[email protected]>

We've been running into issues trying to install an older version of
apkdiff on various machines after bumping the version in a PR.  Avoid
this by always attempting to uninstall apkdiff first.  The uninstall
exit code is ignored as uninstall attempts will error if the tool is not
already installed.

CI is failing with:

    The pipeline is not valid. Could not get the latest source version
    for repository xamarin/xamarin-forms-samples hosted on
    https://github.com/ using ref refs/heads/master. GitHub reported
    the error, "No commit found for SHA: refs/heads/master"

The `master` branch changed to `main` in xamarin/xamarin-forms-samples.

Several repos we are cloning in `azure-pipelines.yaml` are not actually
used anymore. We should just remove these to solve the issue.

…#5898)

Context: https://github.com/dotnet/designs/pull/188/files#diff-8fcaa29d8e6f00b34b3cb1830d93f33e75f04424780a66a3c658c7021048e74fR125
Context: https://github.com/NuGet/NuGet.Client/blob/c529bd75d247430ed19b1713041de0b5b240ef0d/src/NuGet.Core/NuGet.Build.Tasks.Pack/NuGet.Build.Tasks.Pack.targets#L220-L281

The `$(PackageId)` of our workload `.nupkg` needs to be:

	Microsoft.NET.Sdk.Android.Manifest-6.0.100

While the `$(PackageVersion)` remains the same as before.

The layout on disk will change to:

	dotnet\sdk-manifests\6.0.100\Microsoft.NET.Sdk.Android\
	    WorkloadManifest.json
	    WorkloadManifest.targets

Note that `.Manifest` and `-6.0.100` are not in the folder name
on disk.

The generated filename will be e.g.

	Microsoft.NET.Sdk.Android.Manifest-6.0.100.11.0.200-ci.microsoft-net-sdk-android-manifest.255.nupkg

We could find no way to "visually separate" the ".NET version band"
of `6.0.100` from the Microsoft.NET.Sdk.Android version of `11.0.200`.

Additionally, update `version` in `WorkloadManifest.json` so it
contains the proper version for our workload.  This used to not be
possible because `version` was a `long`, but it now is a `string`
where we can put our version.

…5906)

Point to Binding Troubleshooting Guide:

  * https://github.com/xamarin/java.interop/wiki/Troubleshooting-Android-Bindings-Issues

Add hints to include `.jar`/`.aar`/diagnostic log.

Context: https://devdiv.visualstudio.com/DevDiv/_build/results?buildId=4728381&view=ms.vss-test-web.build-test-results-tab&runId=21435278&resultId=100052&paneView=attachments

CI on some of our release branches is failing with errors such as:

    UnnamedProject.csproj: warning MSB4242: The SDK resolver "Microsoft.DotNet.MSBuildWorkloadSdkResolver" failed to run. An item with the same key has already been added. Key: microsoft-android-sdk-full
    Microsoft.NET.Sdk.ImportWorkloads.props(14,3): warning MSB4242: The SDK resolver "Microsoft.DotNet.MSBuildWorkloadSdkResolver" failed to run. An item with the same key has already been added. Key: microsoft-android-sdk-full
    Microsoft.NET.Sdk.ImportWorkloads.props(14,38): error MSB4236: The SDK 'Microsoft.NET.SDK.WorkloadAutoImportPropsLocator' specified could not be found.

This could happen if both directories exist:

    dotnet/sdk-manifest/6.0.100/Microsoft.NET.Workload.Android
    dotnet/sdk-manifest/6.0.100/Microsoft.NET.Sdk.Android

Which would define the same Android workload twice.

xaprepare was setup to clean certain folders in
`$(AndroidToolchainDirectory)\dotnet`, but also needs to delete:

* sdk-manifests/6.0.100/*Android*
* template-packs/*Android*

I also changed some of the string comparisons to use
`StringComparison.OrdinalIgnoreCase`.

Context: dotnet/runtime#51274

In .NET 6, `libSystem.Security.Cryptography.Native.OpenSsl.so` needs
to be loaded and initialized in order for `System.Security` to be
usable.

Previously, nothing ensured that the library was loaded, which would
result in SIGSEGVs at runtime:

	[monodroid-assembly] Caching p/invoke entry libSystem.Security.Cryptography.Native.OpenSsl @ AndroidCryptoNative_CipherCreate
	[monodroid] MonodroidRuntime::monodroid_pinvoke_override ("libSystem.Security.Cryptography.Native.OpenSsl", "AndroidCryptoNative_CipherCreate")
	[libc] Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x0 in tid 5002 (anyname.Android), pid 5002 (anyname.Android)

Workaround this problem by updating `MonoPackageManager.java` so that
`System.Security.Cryptography.Native.OpenSsl` is always loaded from
Java as part of process startup.

This is not a desirable solution, as we want to keep *required*
process startup overheads as small as possible.  Thus, we wish to
remove this workaround in the future, once a proper solution is found.

…#5914)

Fixes: #5838
Context: e0da1f1

Partially reverts 522d7fb which, reverted d13d0f9.

The [`$(AndroidEnablePreloadAssemblies)`][0] property controls whether
or not *all* `.dll` files contained within a `.apk` are loaded during
process startup.  *Not* doing so reduces process startup times, which
is desirable, but this also caused certain Xamarin.Forms apps to fail
to run as they previously had, as not loading all assemblies during
startup broke their Dependency Injection infrastructure.

For .NET 6, we feel we have *some* "wiggle-room" to change default
semantics, so for .NET 6 projects set the default value of
`$(AndroidEnablePreloadAssemblies)` to False, so that assemblies are
*not* pre-loaded during process startup.

`$(AndroidEnablePreloadAssemblies)` can be set to True within the
app's `.csproj` file to return to "legacy" semantics.  This will cause
all assemblies to be loaded during startup, with a commensurate
increase in app startup overheads.

[0]: https://docs.microsoft.com/en-us/xamarin/android/deploy-test/building-apps/build-properties#androidenablepreloadassemblies

Changes: dotnet/installer@eceded1...8e4d77c
Changes: dotnet/linker@307f6b0...4afa105

* Update dependencies from https://github.com/dotnet/installer build 20210505.8

Microsoft.Dotnet.Sdk.Internal
 From Version 6.0.100-preview.5.21252.3 -> To Version 6.0.100-preview.5.21255.8

Dependency coherency updates

Microsoft.NET.ILLink.Tasks
 From Version 6.0.100-preview.5.21229.1 -> To Version 6.0.100-preview.5.21254.1 (parent: Microsoft.Dotnet.Sdk.Internal

* Update .apkdesc files

Co-authored-by: Jonathan Peppers <[email protected]>