I've tried to do it using the "press power button" workaround but this way it mute the ringer.
So I've tried changing the "Set System Setting with category System, Name screen_off_timeout" with value 1000 ,
sleep for 2 seconds and so on but the screen don't turn off and the flow end with an error :
something like "setting not verified": but I have seleced the "I have verified the setting";
maybe because the minimum timeout allowed on my samsung device is 15 seconds?
I've tried again using "press power button" workaround and set the speakers on again:
the result is that the screen turn on again and the ringer is still muted.
