Pausing the transient-hide activities immediately

...when the transient-launch is set to resume-while-pausing

In the legacy transition, the previous top activity is paused
immediately when transition is completed while swiping up to
return to home because the home activity is resume-while-pausing=true.
Somehow, the home activity is already resumed due to transient
launch in shell transition and therefore the ATM would wait for
the previous activity to be paused before able to start new activities.

Bug: 304181511
Test: atest TransitionTests
Test: swiping up to home
Change-Id: I397522c3725c348f9236ca300e4979f38f9e2d0a