Dont create a dummy animation for a transferred animation

When multiple windows get created at once, multiple starting windows
will be created as well. The first window will get an animation and a
dummy animation. If another window will get shown shortly after, it
will receive the animation of the first starting window. However, no
new dummy animation should be created for it since otherwise it might
never get an animation end notification.

This CL also reverts previously added changes to ignore dummy animations.

reverted change: Ie907d31f51e130e245a70249a983d490f3d42b21

Bug: 21643278
Bug: 21403998
Change-Id: I228d77a2d9c3597df0eb9c340a65c0c592c35ce6