Revert "Revert "Enable FLAG_SLIPPERY window flag when swipe down on workspace""

This reverts commit c4c8b3c69597ac5fdd0c29124cb1e5fb70873a55.

Reason for revert: Re-enabling for R1

Change-Id: Id6706c548dcc9debbfaf2069164636bc22aa9b5e
2 files changed