echo test asks user before audio is ready

problem

• echo test shows the question "thumbsup/down" before the audio is ready (up to 10s earlier)
  • no audio during this time
• audio goes into error-state, if user clicks thumbsup before audio is actually ready
  • user has to wait until the echo is actually audible before pressing thumbsup

goal

• the echo test should display the wait screen "establishing audio connection" until the audio is actually ready and only then ask the user

additional info

• reproducible with https://git.fairkom.net/chat/fairblue/-/tags/release_211114
• vanilla bbb 2.3.14 or 2.3.15 do not have this bug (they wait until audio is actually working)