No java output for parcelable declaration

The AIDL compiler no longer generates an empty Java file for parcelable
declaration, which was the behavior before the AIDL compiler refactoring
happend for Android10. The platform build system now is okay with no
output because the generated Java files are zipped to a srcjar.

Test: run aidl_unittests
Change-Id: Iaa9c78c5df06afee165462db05c6dc6e11a1ba8a
3 files changed