Fix package name reporting in MediaDrm metrics.

The app package name was not previously reported in drm metrics. This
change reports the app package name as returned from the vendor metrics.

This is part of the fix. The other change will go into another project.

Bug: 64584568

Test: Unit tests, GTS tests, and Google	Play.
Change-Id: Iee36d5203364c5f80a8b0fe9d9bbf5c167abefd1