[openSUSE] Docker start failure in Leap 15.1 RC

[FroggyFlox]

In openSUSE Leap 15.1 RC, the rock-on service cannot be turned ON as the docker service fails to start with the following error:

CommandException: Error running a command. cmd = /usr/bin/systemctl start docker. rc = 5. stdout = ['']. stderr = ['Failed to start docker.service: Unit containerd.socket not found.', '']

Upon closer inspection, it appears the docker.service file was updated in the corresponding distro package, creating the need for our docker-service.py to be updated accordingly.
Interestingly, the distro package docker.service file in Leap 15.1 RC is now identical to the one in the most recent Tumbleweed (as of this writing), which means we may be able to simplify our docker service configuration in openSUSE.