Add task to list before looking it up.

Rearranging the order of operations allows a newly added task to be
bumped to the top during window sorting. Also, redundant calls moving
the home task to the bottom when moving an app task to the top are
removed.

Maybe fix 10858941.

Change-Id: Ic42d2e7045175384591644675dd0e8013a7c7528
1 file changed