Presubmit test for PackageManager

Added PackageManagerPresubmitTests. testPrivAppPermissions method
tests that core apps like systemui are getting all requested
signature|privileged permissions.

Test: PackageManagerPresubmitTests passes
Bug: 32935038
Bug: 31008485
Change-Id: I31c5c1a2613b8c1ddf927d2708d0361407342b87