I have a listview that will be filled with AsyncTask and at the bottom edge of the app I need to show a fixed overlay layout like this:
As Daniel has suggested, use a RelativeLayout because it allows stacking of components(same with FrameLayout and SurfaceView). The following code will give you the layout you are looking for:
In the code above, the color hex values used for transparentBlack is #95000000 and white is #ffffff.
Here is an excellent tutorial on the basics of UI design in android: Android User Interface Design: Layout Basics.