Copy common resources between styles

The docuemntation of setTo states that the resources two styles from
different AssetManagers have in common will be set in the destination
theme. This change adds this functionality. The package ids of the
attributes, the package ids of reference values, and the cookie of
attribute values have to be rewritten to match the destination
AssetManager. This change can later be made more generic if rewriting
references between packages is needed elsewhere.

Bug: 115897657
Test: libandroidfw_tests and manual test of app specified in the bug
Change-Id: Iee999ea2cc8473168cac11aaf3c34e14c958e5ae