Cancel recents animation to app when new task is launched while gesturing

- A bit of a degenerate case, but if a new task is received while
  the user is swiping up (but not yet released), none of the usual
  signals will finish the recents animation (it's not considered
  being in overview so we don't launch it, it's not a quickswitch
  since we haven't launched any new tasks ourselves).  As a result,
  nothing happens (we don't finish the animation, and the new task
  is never shown to the user as a result).

Bug: 271188120
Test: Start a gesture, in parallel run:
      adb shell am start -n com.android.settings/.Settings

Change-Id: I5215ee87f761c837db9f764bd5d8135e55fa0a21