Move screenshotting of the task earlier prior to the display change

- When canceling, snapshot the pausing tasks when handling the request
  for the display change transition otherwise the display change may
  affect the task snapshot data and report properties for the snapshot
  in the new orientation.

Bug: 278189494
Test: Open letterboxed app and rotate while in overview
Change-Id: Ifb66f4b187ee7e3635127e8f503e84d2b038345c