[release/10.0.1xx-preview3] [Mono.Android] prefix `Microsoft.Android.Runtime` namespace with `_`#9998

jonpryor merged 2 commits intorelease/10.0.1xx-preview3dotnet/android:release/10.0.1xx-preview3from

dev/peppers/release-Microsoft.Android.Runtimedotnet/android:dev/peppers/release-Microsoft.Android.RuntimeCopy head branch name to clipboard