I followed this post below to make a diy ambilight for my computer
All is working well - but looking at guides for ambilight solutions for TVs, it requires an hdmi 4k converter, plugged into a Roku or Chromecast. Is it possible If using neither, and just using AndroidTV?
It seems like it would be easier to just buy some dimmable 6500K LED strip lights (or tape if you're handy) if you are just looking for literal bias lighting.
Colored lighting isn't great for TV/movie viewing. It messes with your perception of on screen colors. 6500K bias lighting is great, though. I very much liked the white mode on my old Philips TV.
You could try installing this: https://play.google.com/store/apps/details?id=com.abrenoch.hyperiongrabber&hl=en_AU&gl=US on your android TV. Looks like it will take whatever the android tv has on display and send that to the LED controller