Action "Set Audio Volume" should support variables

[kintrupf]

Right now one can only select a fixed volume with the slider.

[Martin]

You can use action Restore Audio Volumes which restores the volume from following global variables:
global_volume_alarm
global_volume_dtmf
global_volume_music
global_volume_notification
global_volume_ring
global_volume_system
global_volume_voice_call

Documentation will be updated with this information.