Revert "Revert "Revert "Removing N from PLATFORM_VERSION_ALL_CODENAMES"""

This reverts commit 091fa1edc91a45413650c7243f16d2aa82e1f61f.

Bug: 29117805
Bug: 28809789
Bug: 29621988
Change-Id: Ia127709ada69444a6c252f3e583835d4a4fcbeb8
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 596e4da..dbfa90a 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -75,7 +75,7 @@
   # 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),NMR1
+  PLATFORM_VERSION_ALL_CODENAMES := $(PLATFORM_VERSION_CODENAME),NMR1,N
 endif
 
 ifeq "REL" "$(PLATFORM_VERSION_CODENAME)"