Fix ALTERNATE_BOUNCER->GONE...

... when face unlock happens fast, before the transition
to ALTERNATE_BOUNCER completes. This matches the logic
for every other transition.

And move the tests to be multivalent

Fixes: 335285286
Test: atest KeyguardTransitionScenariosTest
Flag: N/A
Change-Id: Id16d92a57b19c6664abb029397c0798c8c9e1507