Coffee Break: Fully Release Microphone Track

Summary

In startDisableMediaOnCoffeeBreakListener, disabling media calls LiveKit's setMicrophoneEnabled(false) via changeMedia. By LiveKit default (stopMicTrackOnMute: false), muting the mic only mutes the track and keeps the underlying MediaStreamTrack live, so the OS indicator stays on.

The camera is stopped on mute by default, which is why video behaves

QA Scenario

• Start a coffee break with mic on -> OS mic indicator turns off
• End coffee break, re-enable mic -> audio works on Chromium/Firefox/Safari
• Mic off + camera on entering coffee break -> no errors