add 'force' verification in _volume_upload_image
add 'force' verification in _volume_upload_image

_volume_upload_image API should only support to upload 'in-use' volume to
image when assign 'force' parameter as true value. Now
_volume_upload_image API does not do verification for 'force' parameter,
so we can upload 'in-use' volume to image when assign 'force' parameter
with string value 'false' or 'false111'. This patch add verification for
'force' parameter.

Change-Id: I9e1d0e517d0ff97c136903dd6e50a305e18651f3
Closes-Bug: #1265718

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