Continue with the animation if wallpaper fails to draw

- This is preferable to canceling the animation, which the user just
  interprets as the nav gesture not working, and may fix some cases
  where the user may interpret a swipe up as not working if the wallpaper
  is slow to draw.

Bug: 135536076
Bug: 134091263
Test: atest RecentsAnimationTests
Test: atest RecentsAnimationControllerTests
Change-Id: Icf9ed20971a701a254383c65aa1811a99680ba51