Set the audio output level of a given audio device.
#include <audio/audio_manager_volume.h>
int audio_manager_set_output_level(audio_manager_device_t dev, double level)
The audio device that the new output level is applied to.
The new output level in percentage, 0.00 - 100.0 (e.g. 90.00 = 90%).
The audio_manager_set_output_level() function sets the audio output level of a given audio device.
EOK upon success, negative errno upon failure.