[release-4.14] CNF-13064: IBU: Add automated container storage cleanup to Prep stage

[openshift-cherrypick-robot]

This is an automated cherry-pick of #634

/assign openshift-cherrypick-robot

[openshift-ci-robot]

@openshift-cherrypick-robot: Ignoring requests to cherry-pick non-bug issues: CNF-13064

In response to [this](https://github.com/openshift-kni/lifecycle-agent/pull/637): >This is an automated cherry-pick of #634 > >/assign openshift-cherrypick-robot Instructions for interacting with me using PR comments are available [here](https://prow.ci.openshift.org/command-help?repo=openshift-kni%2Flifecycle-agent). If you have questions or suggestions related to my behavior, please file an issue against the [openshift-eng/jira-lifecycle-plugin](https://github.com/openshift-eng/jira-lifecycle-plugin/issues/new) repository.

[openshift-ci[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: donpenney

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/openshift-kni/lifecycle-agent/blob/release-4.14/OWNERS)~~ [donpenney] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment