Revert "Simplify UIDs in PacakgeInstaller app"

This reverts commit 00aeda0a.

Reason for revert: <Potential culprit for b/330634051  - verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted.>

Change-Id: I50d2918bd2dcd4e69af13c5f551246f66734c158