Given how classically horrible the low-latency Android audio API is--to the point where Google was running panels at I/O that would start with "before we begin, I just want to be clear: we have not fixed it", and everyone I know who did audio tended to be stuck with iOS-only--I can see it having been a short time, but that was many years ago and I don't even think they wrote the audio parts (I think they might have used not just Agora as a service, but the Agora SDK?) so I could see it being a long time... ;P.