Always choose starting window's sync transaction to reparent.

The order of finishSync target can affects the final result of
reparent starting window. That's because there use starting
window's sync transaction for transfer starting window, but choose
activity's sync transaction for attach starting surface to
associatedTask. So if transfer starting window happen after
attachStartingSurfaceToAssociatedTask, and the activity's finishSync
occur before window's finishSync, then the final transaction result
will be transfer starting window.

Flag: EXEMPT bugfix
Bug: 349020524
Test: repeat launch app info from launcher multiple times. Also verify
there is regression on 26327083

Change-Id: Ia21930051a132bf87e54f09d52abbd36a87bd0aa