When the touch passes a threashold, we take a snapshot and start the launcher
activity. The launcher displays the snapshot on top of its UI.
As we get further touch events, we move this snapshot and the hotseat in reponse.
Change-Id: I4623676227000afd52805a414a4de499081feced
In QuickStep, adding a placeholder ScrollView and changing the state logic
appropriately to handle that
Change-Id: I10223c0692788d6e5dbf8c408c01cafb4e39bd2c