Mute/unmute audio and Enable/disable video on Android

Hello to everyone, I’m trying to implement some controls on my android app using openvidu.
I don’t understand how to implement an enable/disable video on android. I implemented yet disable/enable videoTrack, but screen in remote is black and other participants don’t understand that my android participant has stop to stream (or has mute his mic).
It’s seems that I miss something to notify to others participant that my local streamer has stop to send his media track.