Touch up/cancel over navigation bar will send down event to drag layer

There is no events from nav bar to send to drag layer until crossing the touch
slop on move. If up occurs, sending the touch down event will clear floating
objects such as the folders.

Change-Id: I6095506f505535e04d59c403e539f37e27295470
Fixes: 111008382
Test: open folder, touch an empty space on nav bar