Currently if the Galera master node is rebooted after installation process
a new Galera cluster is build because of the --wsrep-new-cluster present
in the systemd.service file. This commit aims to update this behavior
accordingly.
Closes-bug: #1439197
Change-Id: I3e4c339ea073bd18177bd0625d694ddd0151b14c
(cherry picked from commit 735a760c40)
f5cc0871e6