Don't run face auth if device is going to sleep

Fixes: 245475936
Test: atest KeyguardUpdateMonitorTest
Test: Tested manually: enroll FP & face, lock phone, tap on weather in
smart space on lock screen to show UDFPS bouncer, wait for screen
timeout, face auth shouldn't run just before screen turns off

Change-Id: I34f626322265f85abc112c9cfd4d3d957229bb1a