Add pre-deprecated "after-merge-finish" transaction

* This should not be used except in the rare case where
it needs to "overwrite" an ordered finishT due to the
use of finishWCT (as is the case currently w/ recents).
* We now always move tasks that are opening to the closing
queue if we detect it's a swipe to home

Bug: 320403561
Test: perform quickswitch + swipe-up rapidly
Flag: EXEMPT bugfix
Change-Id: I901736891d1e3e5df481d6a47d43fc34b600d981