Add basic tests for java modules

Java modules have been unused for a few years, add a few very basic
tests to exercise the modules as they are brought up to date.

Test: java_test.go
Change-Id: Ib23fc065674a61308333130ff1a992525b92e705
diff --git a/Android.bp b/Android.bp
index 68b379c..82be0fa 100644
--- a/Android.bp
+++ b/Android.bp
@@ -203,6 +203,9 @@
         "java/java.go",
         "java/resources.go",
     ],
+    testSrcs: [
+        "java/java_test.go",
+    ],
     pluginFor: ["soong_build"],
 }