MTP should be built with SupportedPlatform items for Android, iOS, Browser #5039
Description
We should have the following when building on MTP so that we get warnings from unsupported APIs and we explicitly decide how to handle for the unsupported platform
<ItemGroup>
<SupportedPlatform Include="android" />
<SupportedPlatform Include="ios" />
<SupportedPlatform Include="browser" />
</ItemGroup>- Start by core platform, and suppress the warnings
- Gradually work on fixing the warnings (search for CA1416 in the codebase to find suppressions)
- Repeat for extensions gradually