Revert "Swipe-up from the bar area on the home screen should pull up overview"

This reverts commit c5985751.

Reason for revert: Confirmed with Manasi that we don't want to have a different behavior for the trackpad gesture even if it starts from the task bar area. It should be treated the same.

Change-Id: I5817c477968545e452d7600d43825209e2c75c37