Update platform security string to 2017-10-01 in oc-dev Bug:64896113
(cherry picked from commit 80d3742026e1640e3cbcfb2bcbc9244733dc05d4)

Change-Id: I84d39c967ca16e87105299cc5f0baf34b2bbdd61
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 56a4f88..dcf6dd2 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -165,7 +165,7 @@
     #  It must be of the form "YYYY-MM-DD" on production devices.
     #  It must match one of the Android Security Patch Level strings of the Public Security Bulletins.
     #  If there is no $PLATFORM_SECURITY_PATCH set, keep it empty.
-      PLATFORM_SECURITY_PATCH := 2017-09-05
+      PLATFORM_SECURITY_PATCH := 2017-10-01
 endif
 
 ifndef PLATFORM_BASE_OS