Internal version of UMS maintains a self-locking data-structure of user
states that is pushed from ActivityManager. Previously there could
be discrepancies between UMS.isUserUnlockingOrUnlocked and
UM.isUserUnlockingOrUnlocked, which is calling a blocking version
in ActivityManager.
Test: manual + UserManagerTests
Bug: 31995235
Bug: 31833240
Change-Id: Ibafe403f57cd32d9052bb55fe7273a861be1d037