Initial kotlin support

Allow java libraries to specify .kt sources, precompile them with
kotlin, and then pass them in the classpath to javac.

Bug: 65219535
Test: java_test.go
Change-Id: Ife22b6ef82ced9ec26a9e5392b2dadacbb16546f
diff --git a/Android.bp b/Android.bp
index 1153aac..32b89d1 100644
--- a/Android.bp
+++ b/Android.bp
@@ -229,6 +229,7 @@
     srcs: [
         "java/config/config.go",
         "java/config/error_prone.go",
+        "java/config/kotlin.go",
         "java/config/makevars.go",
     ],
 }