LU-17057 tests: check OSCs FULL state when setting GSS flvr

LU-17057 tests: check OSCs FULL state when setting GSS flvr

When setting a GSS flavor, make sure all OSCs are in FULL state, so
that clients refresh their connections with the updated flavor.

Test-Parameters: trivial
Test-Parameters: testgroup=review-dne-selinux-ssk-part-1
Test-Parameters: testgroup=review-dne-selinux-ssk-part-2
Test-Parameters: kerberos=true testlist=sanity-krb5
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I7c43856e7951f23f2299b25e133fea72400daf94
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55628
Tested-by: Maloo <maloo@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>