DO NOT MERGE : Update Security String to 2017-05-01 on mnc-dev am: 07a0f6968d am: 5281508c37 am: bb768aa837 am: 92380f630e  -s ours am: b62cd71b07 am: 5bb7f611ac am: af68a49351  -s ours
am: 5a2284cb86  -s ours

Change-Id: Ia94a68649f2faf6c53ef6859dfc6cdfd3d29429f