Ensure transfer starting window transaction occur in order.

There won't collect activity immediately while create task fragment,
so there could use pending transaction while associate starting window
with task, and if any other reparenting transaction wasn't apply in
shell side, the transaction order may went wrong.
Checking whether there needs to collect activity before associate
starting window. So the transaction will apply in order.

Bug: 325945660
Test: Cold launch app info from TaskBar while recents is playing
several time, verify the reparent transaction should occur in order.

Change-Id: I5be1859a6ff779e750caffcf8b21497ff9e16b2f