Disable secondary_user_on_secondary_display for CtsMediaBetterTogetherTestCases

MediaRouter2 does not support visible background users but
secondary_user_on_secondary_dispaly was accidantally enabled in a bulk
update without proper testing.

Bug: 368616719
Bug: 369924507
Test: atest CtsMediaBetterTogetherTestCases
Change-Id: Ia60bbad651ed296cb4f0fbfb7222b640f8e71777