Fixity Fix

dotnet/java-interop#1302 fixed the
`Could not determine Java type corresponding to System.Byte[]` crash.

What replaced it was:

    Mono.Android.NET_Tests, Java.InteropTests.JnienvTest.NewObjectArrayWithNonJavaType / Release
    System.ArgumentException : Could not determine Java type corresponding to System.Type, System.Private.CoreLib, Version=10.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e. Arg_ParamName_Name, type

The deal is that [`JavaNativeTypeManager.ToJniName(Type)`][0]
defaults to using `java/lang/Object` if there is no type mapping.

This is "reasonable" because of the "auto-box into
`Android.Runtime.JavaObject`" behavior, meaning it *is*
possible to create a Java array that "holds" `System.Type` instances.
(Because the Java-side array is actually a `java.lang.Object[]`, each
instance of which is an `Android.Runtime.JavaObject`, which in turn
holds the `System.Type` instance.)

However, this is *not* a semantic that
`JniRuntime.JniTypeManager.GetTypeSignature()` maintains, and thus
this was lost in 1b1f145.

Update `JNIEnv.FindClass(Type)` so that if `.GetTypeSignature()`
can't find the typemapping, default to `java/lang/Object`.

This allows all tests to pass, locally.

[0]: https://github.com/dotnet/java-interop/blob/62635a3ffee4c9ec421eb029b86e61267a544f92/src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings/JavaNativeTypeManager.cs#L164-L168

Author: jonpryor

src/Mono.Android/Android.Runtime/JNIEnv.cs

@@ -254,20 +254,21 @@ public static unsafe IntPtr CreateInstance (Type type, string signature, params
 
 		public static IntPtr FindClass (System.Type type)
 		{
+			int rank = JavaNativeTypeManager.GetArrayInfo (type, out type);
 			try {
 				var sig  = JNIEnvInit.androidRuntime?.TypeManager.GetTypeSignature (type) ?? default;
 				if (!sig.IsValid || sig.SimpleReference == null) {
-					throw new ArgumentException ($"Could not determine Java type corresponding to `{type.AssemblyQualifiedName}`.", nameof (type));
+					sig = new JniTypeSignature ("java/lang/Object");
 				}
+				sig = sig.AddArrayRank (rank);
 
 				JniObjectReference local_ref = JniEnvironment.Types.FindClass (sig.Name);
-				IntPtr global_ref = NewGlobalRef (local_ref.Handle);
+				IntPtr global_ref = local_ref.NewGlobalRef ().Handle;
 				JniObjectReference.Dispose (ref local_ref);
 				return global_ref;
 			} catch (Java.Lang.Throwable e) {
 				if (!((e is Java.Lang.NoClassDefFoundError) || (e is Java.Lang.ClassNotFoundException)))
 					throw;
-				int rank = JavaNativeTypeManager.GetArrayInfo (type, out type);
 				RuntimeNativeMethods.monodroid_log (LogLevel.Warn, LogCategories.Default, $"JNIEnv.FindClass(Type) caught unexpected exception: {e}");
 				var jni = Java.Interop.TypeManager.GetJniTypeName (type);
 				if (jni != null) {