[DO NOT MERGE] Updating Security String to 2017-09-01 Bug:63846344 am: 4061effbfe am: e29d61d582 am: 775c752f51  -s ours
am: 6399f470f6  -s ours

Change-Id: Ife92877c9c37bd55f37a448a40a6d05e82c62781