*UPDATE* Final key mappings I found below
I'm got my Flirc working with Android TV. A USB keyboard works just fine with a microUSB adapter. Here's the key mapping I found
up = up
down = down
left = left
right = right
play/pause = enter
back = backspace/esc
search = Super (Windows) - could not map
home = alt+esc (doesn't close apps*)
I got everything working except for search and home. Search isn't really needed because it only accepts voice search by default so it looks for a bluetooth mic