Fix wallpaper crop during unlock animation

Do not crop wallpaper if the wallpaper target is animating but stack
clip mode is not STACK_CLIP_AFTER_ANIM. We can't crop wallpaper with
final bounds as the crop needs to apply before the transform.

bug: 28887408
Change-Id: I62b9a5ca818c3ca8d0af26d807318f63747b8ac4