[DO NOT MERGE] Update Security String to 2017-04-05 for mnc-dev am: af15999c69 am: f23c50fe08 am: ed7c7adb7e am: 46594018ce  -s ours am: acc43b9d4d
am: cb57c6426e

Change-Id: I35a4e8b066708f0e3ede4778a06b691f12e6f3f5