Address the concurrency of accessibility and ringtone am: 3d8b4a45

                                        audio_devices_t device)

{

    float volumeDB = mVolumeCurves->volIndexToDb(stream, Volume::getDeviceCategory(device), index);

    // handle the case of accessibility active while a ringtone is playing: if the ringtone is much

    // louder than the accessibility prompt, the prompt cannot be heard, thus masking the touch

    // exploration of the dialer UI. In this situation, bring the accessibility volume closer to

    // the ringtone volume

    if ((stream == AUDIO_STREAM_ACCESSIBILITY)

            && (AUDIO_MODE_RINGTONE == mEngine->getPhoneState())

            && isStreamActive(AUDIO_STREAM_RING, 0)) {

        const float ringVolumeDB = computeVolume(AUDIO_STREAM_RING, index, device);

        return ringVolumeDB - 4 > volumeDB ? ringVolumeDB - 4 : volumeDB;

    }

    // if a headset is connected, apply the following rules to ring tones and notifications

    // to avoid sound level bursts in user's ears:

    // - always attenuate notifications volume by 6dB