Maintain if any task has been dismissed in RecentsView state

Fixes an issue in large screen layouts where the task order was
incorrectly being recalculated and the user would see their previous
tasks swap places.

Fix: 352308373
Test: Manual. In tablet view, open several apps, go to Overview, dismiss
 a task so the top row order changes, then swipe down the current
 focused task to resume. Observe order stays the same.
Flag: EXEMPT bugfix
Change-Id: Ic59e3125f69d36ba32d13436dba872f4d3a3d0df