Add test for Java GC for binder objects.

Test: hidl_test_java

Bug: 33042939
Change-Id: I87d9de63834c617a568f7d1795c901fdd4c6f8e0
diff --git a/tests/baz/1.0/IBazCallback.hal b/tests/baz/1.0/IBazCallback.hal
index b59a107..503b970 100644
--- a/tests/baz/1.0/IBazCallback.hal
+++ b/tests/baz/1.0/IBazCallback.hal
@@ -18,4 +18,5 @@
 
 interface IBazCallback {
     heyItsMe(IBazCallback cb);
+    hey();
 };