Updating Security string to 2017-01-01 on mnc-dev

b/32949407

(cherry picked from commit 7224901e6bbf3d4f2d239270850615f7df2c9b81)
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 3c265ec..65bbf74 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -105,7 +105,7 @@
   #  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 := 2016-12-05
+  PLATFORM_SECURITY_PATCH := 2017-01-01
 endif
 
 ifeq "" "$(PLATFORM_BASE_OS)"