idmap: reduce CREATING STRING CACHE verbosity

Change-Id: I7febe358b3b302427650edc1d00772fc9d2d547c
Fix Aapt so that duplicate package ID errors are not incorrectly reported.

Aapt falsely reports package ID conflicts unless base packages are included
in strictly ascending order based on their package IDs. This fix addresses
that issue while still detecting and reporting conflicts correctly when they
actually exist.

Change-Id: Ic8059b87f919641d086df88d1556f5fa0063739f