Only stop face auth if display is off & awake

To avoid the race condition of the display
turning on after the power manager wakeing up signal.

Test: atest KeyguardUpdateMonitorTest
Test: manually trigger face auth from the power button 15 times.
See that face auth runs each time.
Bug: 300226174

Change-Id: Ib58b6f311298d4d0c97c548565f0f046df3f8349