That permission is not available to apps not installed on /system. So even if you manage to grant it it will not work. Also I believe without root above command will fail.
can use this command without root, but you will not be able, to delete system apps with this, for this you still need real root.
the above command can be used, to get greenify and other apps to work, without rooting the watch, but also here, you have to live with some limitations without real root.