Ensure that the layer of topActivity can reparent to rotation leash

When the Transition is before the STATE_PLAYING, the action of reparenting TopActivity's
layer to rotation leash will be placed in syncTransaction.
Finally, syncTransaction will be merged into the Transition, and in the Transition,
TopActivity's layer will be reparented to the target task again.
Since the two reparent actions are submitted in the same Transaction, only the last one takes effect,
causing rotation leash to display no content.

Bug: 308079446
Change-Id: Iad65483569d181496987d997f97243568e784d96