code: public void muteAudio(boolean mute) {
          if ((null != localStream) && isActive()) {
              for (MediaStreamTrack eachTrack : localStream.audioTracks) {
                  eachTrack.setEnabled(!mute);
              }
          }
      }
docs: Mute or unmute the local audio
  
  @param mute If true, mute the audio. If false, unmute the audio