Update README according to the recent channel config change.
Update README according to the recent channel config change.

Change-Id: Ie86b64316c2d7ee65a8086dae57acaf09571be61

naroate/androidtv-sample-inputs,googlesamples/androidtv-sample-inputs,stari4ek/androidtv-sample-inputs,tam1m/SundtekTvInput