Fix a rare issue on iOS, where audio stops after permutting two calls. The AudioUnit re-use logic is modified so that re-use can only happen within the scope of a call, to be compatible with CallKit's policy.
Fix a rare issue on iOS, where audio stops after permutting two calls. The AudioUnit re-use logic is modified so that re-use can only happen within the scope of a call, to be compatible with CallKit's policy.