Cherry pick 'jansmets-gitlab-705-task-runner-tmp' into '1-8-stable'
This change set is cherry-pick as an MR to ensure functionality within the
1.8.x line of releases.
Closes #1305 (closed)
Jansmets gitlab 705 task runner tmp Closes #705 See merge request charts/gitlab!769 (cherry picked from commit 53777bce38de82e10b9d8502f508f5fa1e767868) cebabe72 Persistent storage for task-runner tmp directory. 3080ae10 Updates to finish up change 03978d65 Update MR number in changelog entry 52b63706 Updating task-runner tmp changes a01c52ce Fix path in link to backup docs