Update Security String to 2016-01-01 - DO NOT MERGE

http://b/25819582

Change-Id: I99d8ca004bb5d35613f3a2314597717f6b7c04c7
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 0b47ac0..802c6a2 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -73,7 +73,7 @@
   # 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)"