Adjust the audio output level of a given audio device.
#include <audio/audio_manager_volume.h>
int audio_manager_adjust_output_level(audio_manager_device_t dev, double level)
The audio device that the new output level is applied to.
The change in level of the audio output in percentage (e.g. 10.00 = 10% increase, -10.00 = 10% decrease)
The audio_manager_adjust_output_level() function adjusts the audio output level of a given audio device.
EOK upon success, negative errno upon failure.