Fixed issue with not force resizing a task when drag ends.

We were checking mResizing when the drag ends to see if we
should force resize, but it was being set to false just before
the force resize check in endDragLocked.

Also, don't call AM to resize task if bounds isn't going to change.

Change-Id: Ice2c32a0f15f7489a7c80f21bd79c31104ba4487