[JIRA] (OVIRT-1945) Allow to keep running containers in docker_cleanup

Allow to keep running containers in docker_cleanup -------------------------------------------------- Key: OVIRT-1945 URL: https://ovirt-jira.atlassian.net/browse/OVIRT-1945 Project: oVirt - virtualization made easy Issue Type: Improvement Components: oVirt CI, Standard CI (Freestyle), Standard CI (Pipelines) Reporter: Daniel Belenky Assignee: infra Labels: standard-ci docker_cleanup.py stops all running containers before it removes the images. We should make it optional as well as allow whitelisting containers.