The native gluster pool source list data differs from the data used for
attaching gluster volumes as netfs pools. Currently the only difference
was the format. Since native pools don't use it and later there will be
more differences add a more deterministic way to switch between the
types instead.
(cherry picked from commit a92160dbd5416b093c0d99991afe300b9b8572c4)
975fb26272