Set-up transition-related leashes on start transaction

Was previously just setting up on the pending transaction.
Now that operations put on pending transactions will wait
until the ongoing sync transaction, the ordering was wrong.

This CL puts all the changes onto the transition start
transaction.

Bug: 229907442
Test: launch landscape app, close (back) to portrait.
Change-Id: I3e4abc5f8ab80b4cb7a23cd59ca9561d9c953e9f