Update Security String to 2016-09-06 to platform and CTS for September Security (+Quadrooter,-PZ) am: fa721839b2 am: fdf4c8d8a6 am: 21b4d9e01c am: 1f85078b1e am: 782967785e
am: 831bee139d

Change-Id: I7e945fff51f6247d4be73434c3175211604e9495