DPMS: Simplify password sufficiency check on parent

Simplify the password sufficiency check to only pass around the right
user ID, not the parent parameter, which was confusing.

Instead, calls to getActiveAdminsForLockscreenPoliciesLocked pass in the
right user handle, rather than the user handle from the original call
plus the parent parameter

Bug: 172312413
Bug: 165573442
Test: atest FrameworksServicesTests:DevicePolicyManagerTest
Test: atest MixedDeviceOwnerTest MixedProfileOwnerTest OrgOwnedProfileOwnerTest  MixedDeviceOwnerTestApi25 MixedManagedProfileOwnerTest
Change-Id: If1cf5de6ccdf324e2332c0521d4366decdf35804