LU-14808 utils: fix YAML support for DOM files

LU-14808 utils: fix YAML support for DOM files

LFS getstripe never reports LLAPI_LAYOUT_DEFAULT for any stripe
parameter, but 0 or -1 whatever is appropriate.

LU-3285 added extra verification for the DOM parameters, precisely
the stripe count, size and offset have no sense for DOM and are
expected to be LLAPI_LAYOUT_DEFAULT. However, this brakes the yaml
support which uses getstripe output as the wanted values.

Also move the sanity-flr test_6 to ALWAYS_EXCEPT due to LU-14818.

Fixes: 6744eb8eeb ("LU-3285 lfs: add parameter for Data-on-MDT file")
Signed-off-by: Vitaly Fertman <c17818@cray.com>
HPE-bug-id: LUS-10090
Change-Id: Ide0c0fc264c7d1bac487306edf896d90153cf768
Reviewed-on: https://es-gerrit.dev.cray.com/158810
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Reviewed-by: Sergey Cheremencev <c17829@cray.com>
Tested-by: Jenkins Build User <nssreleng@cray.com>
Reviewed-on: https://review.whamcloud.com/44133
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sergey Cheremencev <sergey.cheremencev@hpe.com>
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>