Fixes: https://bugzilla.xamarin.com/show_bug.cgi?id=36485

Under some conditions apps produces an error which does NOT
contain "error <something>:". As a result our regex was not picking
up some errors and was just printing the default error of

	"aapt.exe" exited with code 1

This commit updates the regex to allow for errors which do
not include "error <something>:". And adds a unit test for the
specific test case.

Fixes: https://devdiv.visualstudio.com/DevDiv/_workitems/edit/1139590
Context: dotnet/java-interop@afbc5b3

Changes: dotnet/java-interop@dcaf794...afbc5b3

  * dotnet/java-interop@afbc5b32: [C++] Get rid of compiler warnings (#703)
  * dotnet/java-interop@e295b498: [generator] Fix localization error. (#702)
  * dotnet/java-interop@5a0e37e0: [generator] Support 'managedOverride' metadata (#701)
  * dotnet/java-interop@f6c12ba3: [Xamarin.Android.Tools.Bytecode] Hide Kotlin synthetic constructors (#700)
  * dotnet/java-interop@0334f424: [generator] Hide Java.Lang.Object infrastructure (#698)
  * dotnet/java-interop@c0fcc435: [jcw-gen] Make MSBuild warning/error strings localizable. (#695)

Fixes a handful of warnings reported by GCC and clang when building
for different platforms.

`-Wshadow` warnings:

	monodroid-glue.cc:1609:8: warning: declaration shadows a static data member of 'xamarin::android::internal::MonodroidRuntime' [-Wshadow]
	void *api_dso_handle = nullptr;
	              ^
	monodroid-glue.cc:102:25: note: previous declaration is here
	void *MonodroidRuntime::api_dso_handle = nullptr;

Fix by renaming the local variable.  No functionality changes result
from this fix.

MinGW builds report:

	xa-internal-api.cc: In member function ‘virtual mono_bool xamarin::android::internal::MonoAndroidInternalCalls_Impl::monodroid_get_network_interface_up_state(const char*, mono_bool*)’:
	xa-internal-api.cc:24:86: warning: unused parameter ‘ifname’ [-Wunused-parameter]
	   24 | MonoAndroidInternalCalls_Impl::monodroid_get_network_interface_up_state (const char *ifname, mono_bool *is_up)
	      |                                                                          ~~~~~~~~~~~~^~~~~~
	xa-internal-api.cc:24:105: warning: unused parameter ‘is_up’ [-Wunused-parameter]
	   24 | MonoAndroidInternalCalls_Impl::monodroid_get_network_interface_up_state (const char *ifname, mono_bool *is_up)
	      |                                                                                              ~~~~~~~~~~~^~~~~
	xa-internal-api.cc: In member function ‘virtual mono_bool xamarin::android::internal::MonoAndroidInternalCalls_Impl::monodroid_get_network_interface_supports_multicast(const char*, mono_bool*)’:
	xa-internal-api.cc:34:96: warning: unused parameter ‘ifname’ [-Wunused-parameter]
	   34 | MonoAndroidInternalCalls_Impl::monodroid_get_network_interface_supports_multicast (const char *ifname, mono_bool *supports_multicast)
	      |                                                                                    ~~~~~~~~~~~~^~~~~~
	xa-internal-api.cc:34:115: warning: unused parameter ‘supports_multicast’ [-Wunused-parameter]
	   34 | MonoAndroidInternalCalls_Impl::monodroid_get_network_interface_supports_multicast (const char *ifname, mono_bool *supports_multicast)
	      |                                                                                                        ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~
	xa-internal-api.cc: In member function ‘virtual int xamarin::android::internal::MonoAndroidInternalCalls_Impl::monodroid_get_dns_servers(void**)’:
	xa-internal-api.cc:44:66: warning: unused parameter ‘dns_servers_array’ [-Wunused-parameter]
	   44 | MonoAndroidInternalCalls_Impl::monodroid_get_dns_servers (void **dns_servers_array)
	      |                                                           ~~~~~~~^~~~~~~~~~~~~~~~~
	xa-internal-api.cc: In member function ‘virtual int xamarin::android::internal::MonoAndroidInternalCalls_Impl::monodroid_getifaddrs(_monodroid_ifaddrs**)’:
	xa-internal-api.cc:54:82: warning: unused parameter ‘ifap’ [-Wunused-parameter]
	   54 | MonoAndroidInternalCalls_Impl::monodroid_getifaddrs (struct _monodroid_ifaddrs **ifap)
	      |                                                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
	xa-internal-api.cc: In member function ‘virtual void xamarin::android::internal::MonoAndroidInternalCalls_Impl::monodroid_freeifaddrs(_monodroid_ifaddrs*)’:
	xa-internal-api.cc:64:82: warning: unused parameter ‘ifa’ [-Wunused-parameter]
	   64 | MonoAndroidInternalCalls_Impl::monodroid_freeifaddrs (struct _monodroid_ifaddrs *ifa)
	      |                                                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~

Fix by ignoring the unused parameters only during Windows builds
by using the C++17 attribute `[[maybe_unused]]`

MinGW also reports:

	embedded-assemblies.cc: In static member function ‘static ssize_t xamarin::android::internal::EmbeddedAssemblies::do_read(int, void*, size_t)’:
	embedded-assemblies.cc:663:26: warning: conversion from ‘size_t’ {aka ‘long long unsigned int’} to ‘unsigned int’ may change value [-Wconversion]
	  663 |   ret = ::read (fd, buf, count);
	      |

It is caused by **read**(2) declared in MinGW headers with the third
parameter using an `unsigned int` type instead of the standard
`size_t`.  Fixed by casting properly on Windows builds.