Ensure Recents Go layout finishes before remote anim begins

We would like to assume a correct up-to-date layout for Go recents
before the remote animation begins to ensure correctness of the app to
overview transition and allow for animating all the newly laid out task
views in sync.

We do this by checking if recents is the remote target we are animating
to and if so, checking if the view is ready.  If it is not, then we
delay the remote animation until the layout is finished and everything
is attached.

Bug: 132112131
Fix: 132108983
Test: Run Recents Go, have no tasks in recents, open app, press
overview to go to recents
Test: Test on AOSP and NexusLauncher that animations to Launcher work as
before (both to recents and to home)
Change-Id: Id74d90cffc9fe5db1dbb5fe63b8819c7436fef21