Fix versionlock centos 8

[brad-x]

This resolves a corner case where a RHEL/CentOS 8 system does not have the yum compatibility package installed - everywhere else, the role is using the yum ansible module which detects and uses dnf in recent ansible versions, so the only concern is when:

• System is RHEL/CentOS 8
• System does not have yum installed and only dnf is available to the shell module
• Role variable es_version_lock is set to true, invoking the elasticsearch-RedHat-version-lock.yml playbook.

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[cla-checker-service[bot]]

❌ Author of the following commits did not sign a Contributor Agreement: fc8831a5de0594226eaba494a6e5c9123d76e7d2, 60eb4ccf1ac6318816e9e1c23486343dd70eb51f, , , , , , ,

Please, read and sign the above mentioned agreement if you want to contribute to this project

[brad-x]

I see "CLA Expected - Waiting for status to be reported" - unsure if any further action is needed on my end after signing the CLA - please let me know if this is the case

[darxriggs]

Note: I am not a maintainer.

[botelastic[bot]]

This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. To track this PR (even if closed), please open a corresponding issue if one does not already exist.

[darxriggs]

Please keep it open.

[brad-x]

Also I def signd the contributor agreement, about 3 times. Not sure why it thinks I haven't - possible issue with the commit workflow?

[botelastic[bot]]

This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. To track this PR (even if closed), please open a corresponding issue if one does not already exist.