Revert "Enable media session flag by default"

Revert "Enable session layout for media controls test"

Revert submission 17541694-b227767144-enable

Reason for revert: beta 2 cut was delayed
Reverted Changes:
Ic31ff95d3:Enable media session flag by default
I80160b46d:Enable session layout for media controls test

Change-Id: I66424f4b06ae80c49c552967eaea435b5489afee