Fix scrims not fading in

If the keyguard dismissal animation finishes before the last panel
expansion event, the expansion would never be propagated to the bouncer,
causing it to be stuck in transit forever.

Test: manual with udfps
Test: atest StatusBarKeyguardViewManagerTest
Fixes: 228048755
Fixes: 230195693
Bug: 228361057
Change-Id: I8167b8ab534f2c7e5676d9f2a9f0199f8b952f83