Update Security String to 2016-09-07 to platform and CTS for September
respin

Change-Id: I6ec8efad5b8e45bcf9df79fb54824acc92755a3b
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 5e94645..57a6f8a 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -113,7 +113,7 @@
   # Must be of the form "YYYY-MM-DD" on production devices.
   #
   # If there is no $PLATFORM_SECURITY_PATCH set, keep it empty.
-  PLATFORM_SECURITY_PATCH := 2016-09-05
+  PLATFORM_SECURITY_PATCH := 2016-09-07
 endif
 
 ifeq "" "$(PLATFORM_BASE_OS)"