Comment 7 for bug 1693710

Verified on 9.0-2017-09-01 snapshot
Without proposed: error: argument --metadata: invalid str value: u'test=u\u0442\u0435\u0441\u0442'
With proposed: no errors
root@node-1:~# cinder create --metadata 'test'='тест' 1|grep metadata
| metadata | {u'test': u'\u0442\u0435\u0441\u0442'} |