Add back Java resources to apk without Java code.

Add back Java resources to apk without Java code.

With commit 33360dd56925276e4526f5f52c26423e2bb1a670 we moved Java
resource packaging forward to creation of the jar file. But the Java
resource packaging will be skipped if a module has no Java code at all.
(The build system does support building an apk without Java code.)
In this change we add back the Java resources directly to the built apk
when the apk has no Java code.

(cherry-picked from commit 8b27d1879c5692ebe6c5ac85383981fd96dfe2e1)

Bug: 19947218
Change-Id: I0e1a65a9cbe656974f8ef3923b2f15e9efa5feb9