Enable stopping user with delayed locking for private profile

This change adds a new user property allowLeavingUserUnlockedWhenStopped
that enables the profile to be stopped with delayed locking (i.e.
without the storage being locked). The implementation for quiet mode for
private profiles is also changed to use the stopUserWithDelayedLocking.

Bug: 312184187
Test: atest UserControllerTest, atest UserManagerTest, atest
UserManagerServiceUserTypeTest, atest
UserManagerServiceUserPropertiesTest

Change-Id: I0d44d24d31a4ed9160e73f82a0c93bed28497a33