In order to be sure that devices are being removed from the host,
we should be using the 'force' parameter with os-brick's
disconnect_volume() method.
Closes-bug: #2004555
Change-Id: I63d09ad9ef465bc154c85a9ea125449c039d1b90
(cherry picked from commit 1d8033e54e
(cherry picked from commit a7eed0263e
Conflicts: glance_store/_drivers/cinder/base.py
glance_store/tests/unit/cinder/test_base.py
(cherry picked from commit e9d2509926)
Conflicts: glance_store/tests/unit/test_cinder_base.py
(cherry picked from commit 2830182977)