Fix NPE in RippleDrawable

Invalidate was called while we were busy clearing the list of
animating ripples, which led to an inconsistency between the
ripple count and actual state of the ripple list.

BUG: 17136636
BUG: 17281011
Change-Id: Ifb7be7eb334ad9a44cc3a1e6f55ad1e35218989a
1 file changed