Changelog:
1cf3a57 Revert "switch-to-containers: set and unset osd flags"
693e534 Revert "switch_to_containers: don't set noup flag"
a2556f0 docker: Add Requires on docker service
9a9ef7b docs: Add upgrade operation.
b7ec4a9 switch_to_containers: don't set noup flag
5a41340 switch-to-containers: set and unset osd flags