Remove more profile_owner policy refs

Convert more call sites in the DevicePolicyManagerService to
get the caller and check if it's the DO/PO, instead of relying on
calls to getActiveAdmin with the USES_POLICY_PROFILE_OWNER constant.

The change also makes isDeviceOwner / isProfileOwner return a correct
answer when the caller identity object does not have the admin
component name (as one was not provided by the caller).
In those cases, the UID of the calling app will be used to find
out if it is of an active admin that's a DO/PO.

Bug: 163028934
Test: atest FrameworksServicesTests:DevicePolicyManagerTest
Test: atest com.android.cts.devicepolicy.OrgOwnedProfileOwnerTest com.android.cts.devicepolicy.MixedDeviceOwnerTest com.android.cts.devicepolicy.MixedProfileOwnerTest
Change-Id: I4dd8cb7368d5c66b3ad67317e8bab8f7cecbe899