Change default policy for volume_extension:volume_tenant_attribute
Change default policy for volume_extension:volume_tenant_attribute

The volume_tenant_attribute extension should be accessible by
the owning tenant and the admin. Change default policy from
'rule:admin_api' to 'rule:admin_or_owner'.

Change-Id: I886cd717741c86b5083aeaf16e3e7ea5b4e525b4
Closes-bug: #1269312

hguemar/cinder,dims/cinder,takeshineshiro/cinder,NetApp/cinder,CloudServer/cinder,abusse/cinder,Nexenta/cinder,blueboxgroup/cinder,leilihh/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,ge0rgi/cinder,rakeshmi/cinder,alex8866/cinder,eharney/cinder,petrutlucian94/cinder,mahak/cinder,Hybrid-Cloud/cinder,Thingee/cinder,saeki-masaki/cinder,redhat-openstack/cinder,NeCTAR-RC/cinder,hguemar/cinder,sasukeh/cinder,Accelerite/cinder,phenoxim/cinder,alex8866/cinder,potsmaster/cinder,winndows/cinder,spring-week-topos/cinder-week,manojhirway/ExistingImagesOnNFS,eharney/cinder,tlakshman26/cinder-new-branch,Paul-Ezell/cinder-1,openstack/cinder,scality/cinder,leilihh/cinder,petrutlucian94/cinder,manojhirway/ExistingImagesOnNFS,tlakshman26/cinder-new-branch,dims/cinder,JioCloud/cinder,nexusriot/cinder,Datera/cinder,Hybrid-Cloud/cinder,github-borat/cinder,duhzecca/cinder,scality/cinder,julianwang/cinder,potsmaster/cinder,Nexenta/cinder,Akrog/cinder,saeki-masaki/cinder,openstack/cinder,cloudbase/cinder,abusse/cinder,phenoxim/cinder,cloudbase/cinder,redhat-openstack/cinder,Paul-Ezell/cinder-1,scottdangelo/RemoveVolumeMangerLocks,NeCTAR-RC/cinder,nexusriot/cinder,blueboxgroup/cinder,winndows/cinder,tlakshman26/cinder-https-changes,apporc/cinder,j-griffith/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,spring-week-topos/cinder-week,Akrog/cinder,mahak/cinder,duhzecca/cinder,NetApp/cinder,apporc/cinder,julianwang/cinder,github-borat/cinder,JioCloud/cinder,scottdangelo/RemoveVolumeMangerLocks,j-griffith/cinder,CloudServer/cinder,tlakshman26/cinder-https-changes,nikesh-mahalka/cinder,Datera/cinder,bswartz/cinder,nikesh-mahalka/cinder,takeshineshiro/cinder,Thingee/cinder,bswartz/cinder,Accelerite/cinder,sasukeh/cinder,rakeshmi/cinder,Thingee/cinder