Move PackageManagerInternal to services.jar

The one messy internal caller is the settings provider, so a new @hide
API on PackageManager was introduced to decouple the provider from
LocalServices.  That new entry point is only callable by uid 1000,
paralleling the previous system-caller-only availability.

Bug: 140833849
Test: system boots & runs normally
Change-Id: I93ae38b8f55db7864893a97795aea63014bf5e12