[DO NOT MERGE] Updating Security String to 2017-08-01 on nyc-dev bug:62388772 am: a847c0b23c am: c486b5d047 am: 92c1ca1f5c
am: 93b5d26067

Change-Id: I04be3f2332d926a4b6d3dfb0bcfc921b76e8d9a1