Make the scrim black when waking-up

We need to force an initial black frame because some
display wake-up sequences make the screen blink.
After the black frame, ScrimController will then fade
the black overlay away.

Fixes: 128490955
Test: manually double tap or lift from AOD
Test: atest DozeTriggersTest
Change-Id: I581ddf25542c620268d94da13d7f92538f17870b