[automerger] Fix security hole in GateKeeperResponse. am: e74cae8f7c am: b1141b6ff0 am: 1cd9e8096f am: 6dfc8d8d4d am: a3c1de7e49 am: 4acf4fabf4

Change-Id: Iea8871d4f1a491e4571e2152afbf8855bf451478