I make the ApiDemos project from Android Sample Project. Unfortunately, the project complains invalid resource directory name transition /ApiDemos/res line 1 Android
Yes, transition resources are valid as of API 19.
To get rid of the error, make your build SDK API level 19 or higher.
To do that, in Eclipse/ADT, either
open Project Properties, go to Android and select Project Build Target as API 19, or
edit project.properties
at project root and edit target
to e.g. android-19
Of course, you will have to have SDK 19 installed with SDK Manager and have up-to-date build tools installed.