[BUG]: Audio can not be stopped in bidi-demo

[42nick]

Name of sample affected

adk-samples/python/agents/bidi-demo

Description of issue

The given readme of the bidi-demo is referring to a "Stop Audio" functionality to end the audio session.

After starting the voice interaction the button is simply greyed out. It is not possible to stop the voice mode, see screenshot below:

Environment

e.g.

• OS & Architecture: Ubuntu22.04 with WSL2
• Python version: 3.11.0rc1
• Java version: [e.g. 11] /

Reproduction steps or code

Follow the readme in the bidi-demo and start the gui with: 
uv run --project .. uvicorn main:app --reload --host 0.0.0.0 --port 8000

Error log

N/A