Sync tieProfileLockIfNecessary() with internal main

The internal-first commit ab75d2ce (http://ag/23150174) modified
tieProfileLockIfNecessary(), which is now causing conflicts.  As the
modification to tieProfileLockIfNecessary() (which simply made it not
crash when called with a profile that does not have a parent) does not
depend on the rest of the change, cherry-pick it separately.

Test: atest com.android.server.locksettings
Merged-In: Ib0e4e52c10f0e95913ddfde606d6995de3538f27
Change-Id: I323811363d8801d4f0bc84f241ad042f45bb3358