Fix jank in wake-and-unlock while pulsing

- Don't hide keyguard after the animation is done, because this
would cause a measure in the middle of the fade animation.
- Don't use a layer for the notification panel in this case - we
don't need it and it only adds latency.
- Speed up the whole thing a bit because the animation is now
smoother.

Bug: 23225107
Change-Id: Ie8264c4d0e62bd6a78227e04b9900b4348ddd649