[DO NOT MERGE] Update Security String to 2017-04-05 on lmp-dev am: e2eff3f7ee  -s ours am: ea757ba690 am: 37aab729cf  -s ours
am: 8a59a2eda2

Change-Id: Ieec27d7f6fda4f30bfb1f94d43a48da75bf7cc73