Update udfps animations to use view controllers

Benefits:
- easier testability
- easier to coordinate animating in/out views.

Bug: 175717712
Test: atest UdfpsKeyguardViewControllerTest, manual
- BiometricPrompt (shows no UI, but doesn't crash)
- Enrollment, pulling down shade still has the same bugs
as before
- Keyguard, go to bouncer/shade

Change-Id: If0e97a6e95e5cb612a91b8ebc6ed865de2132874