Don't move down all apps container when touching near scroll bar.

Previously we were using any touch outside of the panel to move
the container, but we want to check this last, after checking if
the touch is near the scrollbar (in which case it should intercept
instead).

Test: Manual
Flag: N/A
Fix: 236661990
Change-Id: I518c546356d1f6c6cedf4b31fa621295dd090175