Run CD transitions on separate track than recents transitions

When the recents transition is running, let transitions with window
containers on different display run in parallel. This fixes an issue
where closing a task in CD while recents is running in the primary
display keeps the task surface (and decoration) visible because recents
was still running, and additional attempts to close it would lead to a
crash trying to find the now removed task.

Flag: com.android.window.flags.parallel_cd_transitions_during_recents
Fix: 416499938
Test: with a couple of desktop tasks open in CD, swipe up on the primary
display to invoke recents transition, then without releasing the gesture
close one of the tasks in the CD - verify the task closes with its
normal animation
Test: atest WmTests:TransitionControllerTest

Change-Id: I3d129369233ba579f0ab2d0039c9704822e9f7ea