Add the LiveWallpaper sample as prebuilt to the SDK system image.

Change-Id: I5a1b0d2e383b757e52879792ee80dbd61f97f9a4
diff --git a/target/product/sdk.mk b/target/product/sdk.mk
index edd79d6..e571f9e 100644
--- a/target/product/sdk.mk
+++ b/target/product/sdk.mk
@@ -29,7 +29,8 @@
 	LiveWallpapersPicker \
 	ApiDemos \
 	GestureBuilder \
-	SoftKeyboard
+	SoftKeyboard \
+	CubeLiveWallpapers
 
 PRODUCT_PACKAGE_OVERLAYS := development/sdk_overlay