I am using the hue Ambilight app on my Shield. It is great when using YouTube as the comor match the screen. The issue is you need to select the lights (with a checkbox) and click the button start Ambilight). On the old Shield os this worked great but in the Oreo update when I back out of it it turns off the app.
I would like to have this turn on and start when the shield turns on. Is this possible since it needs the button to be pressed?
Haven't looked into it, but check and see if Tasker is available for Androidtv. It can automate anything based on triggers.