Add MNC as a valid codename in master.

Change-Id: I76e84fd75e16a75fcec61f5a738164fce5a86627
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 01bae4a..f1aaff2 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -64,7 +64,7 @@
   # This is all of the development codenames that are active.  Should be either
   # the same as PLATFORM_VERSION_CODENAME or a comma-separated list of additional
   # codenames after PLATFORM_VERSION_CODENAME.
-  PLATFORM_VERSION_ALL_CODENAMES := $(PLATFORM_VERSION_CODENAME)
+  PLATFORM_VERSION_ALL_CODENAMES := $(PLATFORM_VERSION_CODENAME),MNC
 endif
 
 ifeq "" "$(DEFAULT_APP_TARGET_SDK)"