Request: show samples of using in a live wallpaper

[AndroidDeveloperLB]

Was suggested to me to move from here: https://github.com/android/renderscript-samples/issues/14

Examples of basic and cool samples:

1. Showing a simple image with a background
2. Showing a video (mp4 and animated GIF/WEBP) with a background
3. The old live wallpapers back in Nexus days. Video to show what I mean: https://www.youtube.com/watch?v=Hz1YBcYw_qE (I like the spinning galaxy one)