SurfaceFlinger: Fix layer creation race

While we create a new layer, the main thread may wake up and set the
layer parent which means we will start traversing the layer parents in
the binder thread. Fix this by updating the transform hint which checks
the parents before pass the layer creation request to the main thread.

Change-Id: Icb87fb4c33bb3a110169d885398f628df319de88
Test: presubmit
Fixes: 243122612