fix: fully-qualified enumerators for Java backend

In the Java backend, enumerators should be fully qualified when used as
default value or const value.

This was missing in 690f584f7f1a5510badc8f9c27417be3d5543e35.

Bug: 142893595
Test: aidl_unittests
Change-Id: I08ed5c6f1e7aa2db81294183393bf0b50103499b
2 files changed