Add new facility to have multiple active codenames.

Use this to have both L and KKWT.

Change-Id: I78cd5ed2dcffab9e93030184ba6f9eb9a6a3cba5
diff --git a/core/Makefile b/core/Makefile
index 5966a3a..9739730 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -203,6 +203,7 @@
 			PLATFORM_VERSION="$(PLATFORM_VERSION)" \
 			PLATFORM_SDK_VERSION="$(PLATFORM_SDK_VERSION)" \
 			PLATFORM_VERSION_CODENAME="$(PLATFORM_VERSION_CODENAME)" \
+			PLATFORM_VERSION_ALL_CODENAMES="$(PLATFORM_VERSION_ALL_CODENAMES)" \
 			BUILD_VERSION_TAGS="$(BUILD_VERSION_TAGS)" \
 			TARGET_BOOTLOADER_BOARD_NAME="$(TARGET_BOOTLOADER_BOARD_NAME)" \
 			BUILD_FINGERPRINT="$(BUILD_FINGERPRINT)" \
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index e16383b..432391f 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -60,6 +60,11 @@
   # This is the current development code-name, if the build is not a final
   # release build.  If this is a final release build, it is simply "REL".
   PLATFORM_VERSION_CODENAME := L
+
+  # 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),KKWT
 endif
 
 ifeq "" "$(DEFAULT_APP_TARGET_SDK)"