Fix logic problems in AnimationDrawable and View.

1. View now checks both queues when unscheduling runnables,
fixing the case where work was scheduled pre-attach, and unscheduled
post-attach.

2. AnimationDrawable avoids posting duplicate runnables when rescheduling
itself.

3. Decouple is-animation-running state from current frame pointer in
AnimationDrawable.  Some calls init to the first frame, but do not
kick off the animation.

4. Remove workaround in SystemUI's AnimatedImageView (status bar icon)
now that the underlying framework issues are fixed.

Bug:11694594
Change-Id: I77ca6bd80262f7edcf980b2d7efc2592f8051f29