[DO NOT MERGE] Updating Security String to 2017-08-01 on nyc-dev bug:62388772...

[DO NOT MERGE] Updating Security String to 2017-08-01 on nyc-dev bug:62388772 am: a847c0b2 am: c486b5d0 am: 92c1ca1f  -s ours am: 5cada701  -s ours am: 525c88d2  -s ours am: d9109cc1  -s ours am: a66e843d  -s ours am: e2f98a3f am: 9f58c6ab
am: d7e4ff45

Change-Id: Icf0898f07e226c901c852efbcefaf1b4a55ce47e