Fix NPE in FAB StateListAnimator

- Added workaround for a bug in ValueAnimator that results in a NPE when
  a start delay is set and the anim is later cancelled by the
  StateListAnimator.
- Properly added animators to AnimatorSet using AnimatorSet#Builder.

Bug: 30190459
Change-Id: I51e1c3c3dfcecb5c89c315191a5f054f49f94669
1 file changed