[Java.Interop.Tools.TypeNameMappings] fix ToJniName() (#1198)

Context: dotnet/android#8751
Context: 56b7eeb
Context: 67c079c

dotnet/android#8751 attempts to figure out how Java.Interop
broke xamarin-android.  That investigation eventually resulted in
67c079c, which allowed xamarin-android to *build* again, and
uncovered a unit test failure.

[`JnienvTest.NewObjectArrayWithNonJavaTypeAndEmptyArray()`][0]:

	[Test]
	public void NewObjectArrayWithNonJavaTypeAndEmptyArray ()
	{
	    //empty array gives the right type
	    var array = JNIEnv.NewObjectArray<Type> (new Type [0]);
	    …
	}

started failing:

	Java.Lang.ClassNotFoundException : crc64d04135c992393d83.Type
	----> Java.Lang.ClassNotFoundException : Didn't find class "crc64d04135c992393d83.Type" on path: DexPathList[[zip file "/data/app/Mono.Android.NET_Tests-VrfrXDHT2r32zDG95kFOiw==/base.apk", zip file "/data/app/Mono.Android.NET_Tests-VrfrXDHT2r32zDG95kFOiw==/split_config.x86_64.apk", zip file "/data/app/Mono.Android.NET_Tests-VrfrXDHT2r32zDG95kFOiw==/split_config.xxhdpi.apk"],nativeLibraryDirectories=[/data/app/Mono.Android.NET_Tests-VrfrXDHT2r32zDG95kFOiw==/lib/x86_64, /data/app/Mono.Android.NET_Tests-VrfrXDHT2r32zDG95kFOiw==/base.apk!/lib/x86_64, /data/app/Mono.Android.NET_Tests-VrfrXDHT2r32zDG95kFOiw==/split_config.x86_64.apk!/lib/x86_64, /data/app/Mono.Android.NET_Tests-VrfrXDHT2r32zDG95kFOiw==/split_config.xxhdpi.apk!/lib/x86_64, /system/lib64, /system/product/lib64]]

It turns out, this type is completely wrong?  It should be looking
for `java/lang/Object` instead?

In 56b7eeb, we lost an important detail from the expression:

	// 56b7eeb^
	if (!type.GetInterfaces ().Any (t => t.FullName == "Android.Runtime.IJavaObject")) …

	// 56b7eeb equivalent:
	if (type.GetInterfaces ().Any (t => t.FullName == "Java.Interop.IJavaPeerable")) …

We are missing the `!` !!!

I was able to reproduce this behavior in a test:

	[Test]
	[TestCase (typeof (System.Type), "java/lang/Object")]
	public void ToJniName (Type type, string expected)
	{
	    string actual = JavaNativeTypeManager.ToJniName (type);
	    Assert.AreEqual (expected, actual);
	}

Where `ToJniName()` was returning `crc64d04135c992393d83/Type` instead
of `java/lang/Object`!

After fixing the problem, the test passes.

[0]: https://github.com/xamarin/xamarin-android/blob/0665f449948c43675ec8706a5a2807b5d3f599f7/tests/Mono.Android-Tests/Java.Interop/JnienvTest.cs#L178-L186

Author: jonathanpeppers

src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings/JavaNativeTypeManager.cs

@@ -196,9 +196,9 @@ public static string ToJniName (Type type)
 		// Trimming warnings are not enabled for netstandard2.0 in this project.
 		static bool ShouldCheckSpecialExportJniType (Type type) =>
 #if NETSTANDARD2_0
-			type.GetInterfaces ().Any (t => t.FullName == "Java.Interop.IJavaPeerable");
+			!type.GetInterfaces ().Any (t => t.FullName == "Java.Interop.IJavaPeerable");
 #else
-			IJavaPeerableType.Value.IsAssignableFrom (type);
+			!IJavaPeerableType.Value.IsAssignableFrom (type);
 #endif
 
 		public static string ToJniName (string jniType, int rank)

tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers/JavaNativeTypeManagerTests.cs

@@ -55,5 +55,14 @@ public void LowercaseWithAssemblyName ()
 			Assert.AreEqual ("assembly_mscorlib.system", JavaNativeTypeManager.GetPackageName (typeof (string)));
 #endif  // !NET
 		}
+
+		[Test]
+		[TestCase (typeof (string), "java/lang/String")]
+		[TestCase (typeof (Type),   "java/lang/Object")]
+		public void ToJniName (Type type, string expected)
+		{
+			string actual = JavaNativeTypeManager.ToJniName (type);
+			Assert.AreEqual (expected, actual);
+		}
 	}
 }