Expose internal API to check if the user's password
will be sufficient after profile unification. Also
expose some other helper methods and refactor
DevicePolicyManagerService to unify a few similar
methods that gather admins from user and its profiles.
Bug: 148630506
Fix: 149682344
Test: atest com.android.server.locksettings
Test: atest FrameworksServicesTests:DevicePolicyManagerTest
Change-Id: Ic647c14d5bab7e7337185bc40b1368e42c65f738
de633f32ea