Fixing occasional jump when launching certain apps from Recents.

- Removing code that cleared the pending options for an activity when it
  is fetched by the app.
- Only handle the first window-animation-started callback from the system
  when transitioning out of Recents.
- Add logic in Recents to disable toggling Recents while an activity
  transition has been requested (ie. activity started) and the transition
  actually starting. This prevents some cases where interleaving of the
  transition updates can occur while the app takes a long time to draw
  when it is resumed which could cause animation jumps and weirdness.

Bug: 37277853
Test: Launch between apps quickly, especially those with camera.

Change-Id: I7ff8a83539334a39b0ae049d267d1ab14a38e2f6