qa: fix api failure issue caused during a dashboard test

qa: fix api failure issue caused during a dashboard test

2022-12-28 10:16:47,812.812 INFO:__main__:  File "/home/jenkins-build/build/workspace/ceph-api/qa/tasks/mgr/dashboard/helper.py", line 712, in
2022-12-28 10:16:47,812.812 INFO:__main__:    _validate_json(val[key], sub_schema, path + [key])
2022-12-28 10:16:47,812.812 INFO:__main__:  File "/home/jenkins-build/build/workspace/ceph-api/qa/tasks/mgr/dashboard/helper.py", line 711, in _validate_json
2022-12-28 10:16:47,812.812 INFO:__main__:    result = all(
2022-12-28 10:16:47,812.812 INFO:__main__:  File "/home/jenkins-build/build/workspace/ceph-api/qa/tasks/mgr/dashboard/helper.py", line 712, in
2022-12-28 10:16:47,812.812 INFO:__main__:    _validate_json(val[key], sub_schema, path + [key])
2022-12-28 10:16:47,812.812 INFO:__main__:  File "/home/jenkins-build/build/workspace/ceph-api/qa/tasks/mgr/dashboard/helper.py", line 710, in _validate_json
2022-12-28 10:16:47,813.813 INFO:__main__:    raise _ValError('unknown keys: {}'.format(unknown_keys), path)
2022-12-28 10:16:47,813.813 INFO:__main__:tasks.mgr.dashboard.helper._ValError: In `input['fs_map']['filesystems'][0]['mdsmap']['flags_state']`: unknown keys: {'refuse_client_session'}

Fixes the above failure

Fixes: https://tracker.ceph.com/issues/57090
Signed-off-by: Dhairya Parmar <dparmar@redhat.com>