[DO NOT MERGE] Updating Security String to 2017-08-01 on nyc-dev bug:62388772 am: a847c0b23c am: c486b5d047 am: 92c1ca1f5c  -s ours am: 5cada70115  -s ours
am: 525c88d2c8  -s ours

Change-Id: I76fa61270e0175db6ba51f78c07b231c943387f0