Fix z-order when transfering animations

We need to reparent the transfered leash to the the animation
layer, not the original parent

Test: Open Play Movies, observe correct z-order during cold-launch
Test: go/wm-smoke
Test: SurfaceAnimatorTest
Change-Id: Ic5a68c68514bb3560b6877a9a29c506aeccee2bf
5 files changed