I am trying to build a custom FrankenPhone. I got stuck trying to make it use new device audio device for call. I can initiate it using terminal commands to forward output of one command to the input of another so that my microphone is forwarded to the GSM modem so the person on the other side of the line can hear me.
But I don’t understand why I need to run this command. Why doesn’t android do this by default? Or what needs to happen so that it does it by default?