Do not block moving task to front if recents is not top

Recents may have started a task but the transient transition
is not finished yet, then still allow the started task to
move another task to front.

Bug: 317160303
Test: Use recents to switch task. The started task X starts
      another existing task Y before X completes resume.
      The task Y should be shown.

Change-Id: I35ef4bcad3e9950694ef780262e73666c04ac16d