Fix stuck unlock animation state

When using face unlock without bypass, the user can swipe up to dimiss
the lock screen which will trigger the keyguard going away remote
animation. However, if this remote animation is canceled, the
'playingCannedAnimation' state remains true essentially forever. When
combined with logic in NotificationShadeWindowViewController that
cancels all touches during this animation, the device is left in a
unrecoverable state as sysui cannot be interacted with.

Rename the cancelled parameter to showKeyguard, to make it clear what
the end state will be.

Fixes: 288505944
Test: atest KeyguardViewMediatorTest
KeyguardUnlockAnimationControllerTest
Test: manual - Use face unlock without bypass, then swipe up and hit
power at the same time

Change-Id: I762853d930f02ab0ee7f8cf0216b5aa6d01cf38c
Merged-In: I762853d930f02ab0ee7f8cf0216b5aa6d01cf38c
(cherry picked from commit aed9df4b)