Update Security String to 2016-01-01 to mnc-dev

http://b/25819582

Change-Id: Ie55f9476110b08591da05774f582a6e48ce12de7
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index a67a82e..2939224 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -103,7 +103,7 @@
   # Can be an arbitrary string, but must be a single word.
   #
   # If there is no $PLATFORM_SECURITY_PATCH set, keep it empty.
-  PLATFORM_SECURITY_PATCH := 2015-12-01
+  PLATFORM_SECURITY_PATCH := 2016-01-01
 endif
 
 ifeq "" "$(PLATFORM_BASE_OS)"