services/audiopolicy/config/a2dp_in_audio_policy_configuration.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Bluetooth Input Audio HAL Audio Policy Configuration file -->
<module name="a2dp" halVersion="2.0">
    <mixPorts>
        <mixPort name="a2dp input" role="sink">
            <profile name="" format="AUDIO_FORMAT_PCM_16_BIT"
                     samplingRates="44100,48000"
                     channelMasks="AUDIO_CHANNEL_IN_MONO,AUDIO_CHANNEL_IN_STEREO"/>
        </mixPort>
    </mixPorts>
    <devicePorts>
        <devicePort tagName="BT A2DP In" type="AUDIO_DEVICE_IN_BLUETOOTH_A2DP" role="source">
            <profile name="" format="AUDIO_FORMAT_PCM_16_BIT"
                     samplingRates="44100,48000"
                     channelMasks="AUDIO_CHANNEL_IN_MONO,AUDIO_CHANNEL_IN_STEREO"/>
        </devicePort>
    </devicePorts>
    <routes>
        <route type="mix" sink="a2dp input"
               sources="BT A2DP In"/>
    </routes>
</module>