[CDM] Add CompanionExemptionProcessor

1. Auto revoke exemption now checks if there's any association for the package.
2. Power saver exemption now checks if there's any connected device for
   the package.

Bug: 373957005
Test: manually tested 3 exemptions
Flag: EXEMPT bugfix
Change-Id: I9a8abba1acf13e348d39fa6780955d2393baeec5
4 files changed