Update kg lock icon logic

- don't animate fp => unlock unless udfps was enrolled
- show a static unlock icon if the device wasn't previously locked

Test: manual
  - swipe to unlock
  - face only
  - fp only
  - co-ex
  - removing biometric auth => swipe to unlock
Bug: 193878791
Change-Id: I35d393383674acb03f06ea58fb8aabc2a820ad7c