Get compatibility immediately on initialization

This change acquires the CompatConfig directly. This cuts down on
unnecessary logging and more importantly, gets access to platform config
values earlier during initialization than it would having to wait for
the PlatformCompat instance to be registered in SystemService.

Bug: 142281062
Test: Device boots
Test: atest AppEnumerationTests
Change-Id: I236dde7d897869633eadd2830a9930be0aec0129