tests: Use MD instead of LVM to test available RAID levels (#test)
We are adding LVM RAID raid0 support to blivet so the harcoded
list of supported levels for LVM RAID will be different with
different versions of blivet.
See https://github.com/storaged-project/blivet/pull/1047 for
details.
(cherry picked from commit fabab04e4b8a584eefd16ed22ac27f8f723bdb11)