[automerger] [DO NOT MERGE] Updating security string for nyc-dev to 2018-05-01 bug: 74345861 am: 7c0f23dce5 am: 21f45f7edc am: 5a2c0096d5 am: bc62637ffa skipped: 262656a47f

Change-Id: Ib99dd412a286ea7ce26bf4cc7b3c74f85bf2d401