[Xamarin.Android.Build.Tasks] <GenerateJavaStubs /> generates a shorter acw-map.txt

[jonathanpeppers]

Fixes: https://bugzilla.xamarin.com/show_bug.cgi?id=61073
Context: dotnet/java-interop#227

The Java-to-Managed typemaps list types such as:

android/app/Activity
Android.App.Activity, Mono.Android, Version=0.0.0.0, Culture=neutral,
PublicKeyToken=84e04ff9cfb79065

This is found in the intermediate dir after a build in acw-map.txt,
or $(_AcwMapFile).

Let’s assume you have an Android project with the following
assembly-level attribute:

[assembly:AssemblyVersion("1.0.0.*")]

Then on every build, the typemap is invalidated because your version
number has been incremented.

Changes:

• Bumped Java.Interop to master/429dc2a
• JNIEnv needs to use the shorter type name when calling
  monodroid_typemap_managed_to_java
• GenerateJavaStubs should not be writing lines for
  type.GetAssemblyQualifiedName into acw-map.txt
• JnienvTest needed some updates to use the new type name format
• Wrote a test using [assembly:AssemblyVersion("1.0.0.*")] that
  checks acw-map.txt contents

[jonathanpeppers]

There is probably more to do here, this is the initial PR to see what breaks.

[jonpryor]

JnienvTest.ManagedToJavaTypeMapping() is failing in the macOS+xbuild PR Build:

  Expected: not 0
   But was:  0
 +++++++++++++++++++
STACK TRACE:
  at Java.InteropTests.JnienvTest.ManagedToJavaTypeMapping () [0x00016] in <6c61e4bbfe054677adac786d9e684c35>:0 
  at (wrapper managed-to-native) System.Reflection.MonoMethod.InternalInvoke(System.Reflection.MonoMethod,object,object[],System.Exception&)
  at System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00032] in <808e27c157614d6b865c43847235b62d>:0 

The stack trace doesn't quite make sense, but presumably it's due to line 395:

var m = monodroid_typemap_managed_to_java (typeof (Activity).AssemblyQualifiedName);
Assert.AreNotEqual (IntPtr.Zero, m);

The test likely needs to be updated, as we're no longer using Type.AssemblyQualifiedName in the typemap.* files. This presumably will need to manually generate the value:

var m = monodroid_typemap_managed_to_java ($"{typeof (Activity).FullName}, {typeof (Activity).Assembly.GetName().Name}");

...which should be split out into a helper so line 396 can reuse it.

Additionally, we should probably add a comment for why lines 396-397 are supposed to fail, because I forgot while re-reading the test. (sheepish-grin)

The rationale is that typemap.mj only exists to map names between Java & Managed types. JnienvTest does not inherit Java.Lang.Object, and thus should not be in the typemap.mj files.

[jonpryor]

Comment on the commit message: this commit is actually fixing #61073, so a Context: line isn't appropriate. It should be Fixes: .

[jonpryor]

You're missing a closing ):

Java.Interop/JnienvTest.cs(401,76): error CS1026: ) expected

This prevents it from building.

[jonpryor]

Love the new assert messages! 👍