…b.dll (dotnet#82618)

The legacy Xamarin.Android version of mscorlib.dll differed a bit compared to the .NET Framework mscorlib.dll, mostly because of additions for .NET Standard 2.1 support.

This meant that an assembly which was compiled against that mscorlib expects types there but since we didn't have type-forwarders in our mscorlib.dll shim to point them to the right assembly you'd get a TypeLoadException when running on modern .NET 6 Android.

Fixes dotnet#82193

(cherry picked from commit d8203e7)

…ng.Common.dll (dotnet#82839)

The legacy Xamarin.Android version of System.Drawing.Common.dll contained these types, add forwarders so we don't get a TypeLoadException when using an assembly compiled against that in modern .NET Android.

Fixes dotnet#82829

(cherry picked from commit e486f38)