[DO NOT MERGE] Update Security String to 2017-04-01 on lmp-dev am: ffab6999 ...

[DO NOT MERGE] Update Security String to 2017-04-01 on lmp-dev am: ffab6999  -s ours am: 0f30aa98 am: 05ebddeb  -s ours am: 101c043b am: 58086ff4 am: fec9d767 am: ea0d4b0e  -s ours am: 45deda36 am: 235702c0 am: 6063089d  -s ours am: 7d134815  -s ours am: b05bb3fe  -s ours
am: 7275412c  -s ours

Change-Id: I056f6200a5fc18fb92ca23313f8ffa0201ddde87