Echo while creating audio track

[0k1]

Hello -

I've been trying to use the latest MRTK from release 2.0 branch. Built from source with echo cancellation params added per previous comments in #157. Still the UWP app seems to send audio with echo to the unity app running on Unity 2020.3.19f1. The audio renderer in unity shows that the echo is indeed from the source. Is there a way to stop the echo from the source itself ?

I've used echo cancellation at unity's side to reduce the effects but if built for HoloLens 2 the effects can still be disturbing to the user.

Repro steps :

Run the MRTK WebRTC Test UWP app and try to establish connection with a unity player running the Unity version of MRTK WebRTC.

@djee-ms @jessemcculloch