Update Security String to 2016-09-06 to platform and CTS for September
Security (+Quadrooter,-PZ)

Change-Id: I248efb2cbd877b4954994077df0f90adcf332f4a
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 57a6f8a..18f80ae 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 := 2016-09-07
+  PLATFORM_SECURITY_PATCH := 2016-09-06
 endif
 
 ifeq "" "$(PLATFORM_BASE_OS)"