Do not call setReady(false) when finishing

Before, when there is a collecting transition, finishing activity/task
will unset the ready state. It can cause issue if the existing
transition has already in ready, because there may not be other setReady
call for finishing.

Bug: 183993924
Test: manually on acloud with resolve activity for two launchers
Change-Id: Ibafaf0b9bd7842a30eedbeb02271ab6f96c838ff