N is API 24

Change-Id: I8e4fbc1d64a6cd3eb0b4765f696ae48170264d52
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 1c1e2ca..b7c4542 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -55,7 +55,7 @@
   # intermediate builds).  During development, this number remains at the
   # SDK version the branch is based on and PLATFORM_VERSION_CODENAME holds
   # the code-name of the new development work.
-  PLATFORM_SDK_VERSION := 23
+  PLATFORM_SDK_VERSION := 24
 endif
 
 ifeq "" "$(PLATFORM_JACK_MIN_SDK_VERSION)"