I basically started with Android app development but android gaming makes me fancy of those superb UI's and animations when i get hands on some of them like popular Angry Birds or NFS Shift. What basically comes in question is how to develop those beautiful and superbly sliding and animating UI's?
You roll your own UI library. None of the games you mentioned use the native Android UIs. They have a single Activity with a SurfaceView capable of rendering via OpenGL ES and that's all the Android APIs they use (plus or minus some APIs for file/networking access). The UIs are then drawn via OpenGL ES, animation and other fancy effects are created manually.
Given that I do all this in my sparetime i do not offer personal support, i hope you understand. I however try my best to answer general questions on our forums. If you have any general game development related questions you can catch a couple of knowledgeable developers (and myself) over at http://www.badlogicgames.com/forum.