Question [Q] Using android UI graphics externally?

I would like to use the stock Android GUI graphics in a cross platform API called LibGDX. How would i go about obtaining the Android GUI graphics in .png format, so they can be loaded as standard textures in any application?

I ask because i want to have a standard UI for my application, regardless of the platform it has been deployed to (Windows, Android, etc) instead of having to design one UI in Swing and another in Android...

Any ideas? I would imagine that they should be pretty easy to access, but how?