Don't exempt background mic / camera when device upgrades

Fixes the issue where the platform added preinstalled apps to the
background mic / camera allowlists so they were able to request
these permissions.

Bug: 169856898
Bug: 158311343
Test: Upgrade from R. Upgrade from ToT.
Change-Id: I8ad30cd3d3e30f94b4e42c2bf8acbb0b0e0b7472