Update Security String to 2016-05-01 in preparation for May 2016 Security OTA am: 175b780 am: 274e483 am: 08d9bea am: 6bbd684 am: f32d07d am: 0cf7987
am: ae7c301

* commit 'ae7c3010265171b2c215c5a30049320ba50265a7':
  Update Security String to 2016-05-01 in preparation for May 2016 Security OTA