Handle more Attribute Types when Filtering Assemblies

Fixes #9369

When System.Reflection.Metadata comes across an Attribute
which has a generic, it does NOT return a `TypeReferenceHandle`.
It returns a `TypeSpecificationHandle`.

Tying to cast the type results in the following error

```
System.InvalidCastException: Die angegebene Umwandlung ist ungültig.
error XAFLT7007:    bei System.Reflection.Throw.InvalidCast()
error XAFLT7007:    bei System.Reflection.Metadata.TypeReferenceHandle.op_Explicit(EntityHandle handle)
error XAFLT7007:    bei Xamarin.Android.Tasks.MetadataExtensions.GetCustomAttributeFullName(MetadataReader reader, CustomAttribute attribute)
error XAFLT7007:    bei Xamarin.Android.Tasks.FilterAssemblies.IsAndroidAssembly(AssemblyDefinition assembly, MetadataReader reader)
error XAFLT7007:    bei Xamarin.Android.Tasks.FilterAssemblies.ProcessAssembly(ITaskItem assemblyItem, List`1 output)
error XAFLT7007:    bei Xamarin.Android.Tasks.FilterAssemblies.RunTask()
error XAFLT7007:    bei Microsoft.Android.Build.Tasks.AndroidTask.Execute()
```

So we need to handle this case, and put in place a backup to handle
an `InvalidCastException` so that we never hit this issue again.

samples/HelloWorld/HelloLibrary/LibraryActivity.cs

@@ -16,8 +16,12 @@
 using Android.Views;
 using Android.Widget;
 
+[assembly: HelloLibrary.GenericTest<string>]
 namespace HelloLibrary
 {
+    [AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true, Inherited = false)]
+    public class GenericTestAttribute<T> : Attribute { }
+
     [Activity(Label = "Library Activity", Name="mono.samples.hello.LibraryActivity")]
     public class LibraryActivity : Activity
     {

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/BuildTest2.cs

@@ -1461,5 +1461,48 @@ public void BuildWithJavaToolOptions ()
 				Environment.SetEnvironmentVariable ("JAVA_TOOL_OPTIONS", oldEnvVar);
 			}
 		}
+
+		[Test]
+		public void LibraryWithGenericAttribute ()
+		{
+			var path = Path.Combine ("temp", TestContext.CurrentContext.Test.Name);
+			var lib = new XamarinAndroidLibraryProject {
+				ProjectName = "Library1",
+				IsRelease = true,
+				Sources = {
+					new BuildItem.Source ("Class1.cs") {
+						TextContent = () => """
+							namespace Library1;
+							public class Class1 { }
+						"""
+					},
+					new BuildItem.Source ("GenericTestAttribute.cs") {
+						TextContent = () => """
+							using System;
+							[assembly: GenericTestAttribute<Guid>]
+							[AttributeUsage(AttributeTargets.Assembly, AllowMultiple = true, Inherited = false)]
+							public class GenericTestAttribute<T> : Attribute { }
+						""",
+					},
+				},
+			};
+			var proj = new XamarinAndroidApplicationProject {
+				ProjectName = "App1",
+				IsRelease = true,
+				Sources = {
+					new BuildItem.Source ("Class2.cs") {
+						TextContent= () => """
+							namespace App1;
+							class Class2 : Library1.Class1 { }
+						""",
+					},
+				},
+			};
+			proj.AddReference (lib);
+			using var libb = CreateDllBuilder (Path.Combine (path, "Library1"));
+			Assert.IsTrue (libb.Build (lib), "Library1 Build should have succeeded.");
+			using var b = CreateApkBuilder (Path.Combine (path, "App1"));
+			Assert.IsTrue (b.Build (proj), "App1 Build should have succeeded.");
+		}
 	}
 }

src/Xamarin.Android.Build.Tasks/Utilities/MetadataExtensions.cs

@@ -12,8 +12,23 @@ public static string GetCustomAttributeFullName (this MetadataReader reader, Cus
 		{
 			if (attribute.Constructor.Kind == HandleKind.MemberReference) {
 				var ctor = reader.GetMemberReference ((MemberReferenceHandle)attribute.Constructor);
-				var type = reader.GetTypeReference ((TypeReferenceHandle)ctor.Parent);
-				return reader.GetString (type.Namespace) + "." + reader.GetString (type.Name);
+				try {
+					if (ctor.Parent.Kind == HandleKind.TypeReference) {
+						var type = reader.GetTypeReference ((TypeReferenceHandle)ctor.Parent);
+						return reader.GetString (type.Namespace) + "." + reader.GetString (type.Name);
+					} else if (ctor.Parent.Kind == HandleKind.TypeSpecification) {
+						var type = reader.GetTypeSpecification ((TypeSpecificationHandle)ctor.Parent);
+						BlobReader blobReader = reader.GetBlobReader (type.Signature);
+						SignatureTypeCode typeCode = blobReader.ReadSignatureTypeCode ();
+						EntityHandle typeHandle = blobReader.ReadTypeHandle ();
+						TypeReference typeRef = reader.GetTypeReference ((TypeReferenceHandle)typeHandle);
+						return reader.GetString (typeRef.Namespace) + "." + reader.GetString (typeRef.Name);
+					}
+				}
+				catch (InvalidCastException)
+				{
+					return null;
+				}
 			} else if (attribute.Constructor.Kind == HandleKind.MethodDefinition) {
 				var ctor = reader.GetMethodDefinition ((MethodDefinitionHandle)attribute.Constructor);
 				var type = reader.GetTypeDefinition (ctor.GetDeclaringType ());