Lockscreen launch animations

- Get rid of ActivityManager.dismissKeyguardOnNextActivity, which was
  used for two different things: Dismiss keyguard from somewhere else
  (not really necessary anymore), wait to actually dismiss keyguard
  after the window behind is drawn. Instead, introduce
  keyguardWaitingForActivityDrawn(), and change the semantics where
  necessary.
- Make wallpaper_close_enter consistent with task_open_enter and the
  Keyguard launch animation.
- Close the panel even on lockscreen when launching a notification.
- Block notification shade updates during the collapsing motion so
  notification don't play the disappear animation immediately after
  having launched a notification.

Bug: 15991916

Change-Id: I133c177b84e926c87c1a404ba93d633593fec3ab