[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
am: 3746e17d30

Change-Id: I0289dd868164312ae2702b57893e160e60fcdfee