Bump to xamarin/Java.Interop/main@2573dc8c

Fixes: dotnet/java-interop#835
Fixes: dotnet#5921

Context: dotnet#5894

Changes: http://github.com/xamarin/Java.Interop/compare/12e670a8560f69581d3a3adf0a9d91e8ce8c9afa...2573dc8c84fd4eb68e75bcae73912c26f4942356

  * dotnet/java-interop@2573dc8c: [Java.Interop.Tools.*] IMetadataResolver not TypeDefinitionCache (dotnet#842)
  * dotnet/java-interop@412e974b: Revert "[generator] Disable [SupportedOSPlatform] until .NET 5/6. (dotnet#781)" (dotnet#841)
  * dotnet/java-interop@23baf0bc: [Java.Interop] Fix NRT warnings introduced by targeting 'net6.0' (dotnet#840)
  * dotnet/java-interop@131c1496: [generator] Fix NRE from return type not consistently set (dotnet#834)
  * dotnet/java-interop@100fffc1: [generator] Ensure "global::" is prepended to generic return casts. (dotnet#838)
  * dotnet/java-interop@9b89e90e: [generator] Ignore types without names (dotnet#837)
  * dotnet/java-interop@0e01fb5d: [Java.Interop.Tools.JavaSource] Merge @return block values (dotnet#836)