Surfaces were displaying animations in their entirety for a single
frame before the animation kicked in. This caused a flash on the
screen. By setting the animation to invisible (alpha=0) at their
start it makes no difference if they are displayed.
Fixed bug 6176540.
Removed redundant mDimAnimator.show call.
Change-Id: I47c1b0d38273b011d9115822a8476671d6a050fc