Update bugfix release to Jan 1
(cherry picked from commit 633d9a764893daf70c54ac9a7c827d1408426762)

Change-Id: I1a8633ec780b715f6d17b96f5ca9dc8b209e6b8f
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index d7a882b..956eafe 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -114,7 +114,7 @@
     #  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 := 2017-11-01
+      PLATFORM_SECURITY_PATCH := 2018-01-01
 endif
 
 ifeq "" "$(PLATFORM_BASE_OS)"