Don't switch back to fullscreen camera when flinging

Bug: 7145903
Bug: 7050303
It was very annoying to users to fling in the filmstrip
and end up in the fullscreen camera mode, so disabling
that. Long-term, we want to be smarter about this and
do the zoom to the full-screen if it's a short swipe
rather than a fling.

Change-Id: I40ac4848a267c06fc41e161a7a292b8f03b2ef4c