[DO NOT MERGE] Update Security String to 2017-04-01 on lmp-dev am: ffab69998a  -s ours am: 0f30aa9801 am: 05ebddebe5  -s ours am: 101c043b17 am: 58086ff4aa am: fec9d76740 am: ea0d4b0e54  -s ours
am: 45deda3682

Change-Id: I7b07e9e6d95d9fa6e783ddde5eda3b4b6c0e8727