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

Change-Id: Ia8a4c064fb9a75b18745d0634e20925424d66153