Allow swipe up to go home from overivew during task dismiss animation

Test: go to overview, dismiss a task, swipe up to go home during the
transition (easier to try with animation duraation scaled up)

Bug: 144170434
Change-Id: I28b846b43260179aeac877351a7069743f66f3ea
Merged-In: I28b846b43260179aeac877351a7069743f66f3ea