Don't allow swipe up for all apps above shelf

It's confusing that swiping up and holding on the shelf brings up
overview, but swiping up and holding slightly above the shelf doesn't.
The reason is that a different controller that just went straight to all
apps was used in the second case; removing that reduces confusion.

Change-Id: Idceed909cd51f27e1d6ffc97d874e5f664d1fc1d