PodVolumeBackup fails on completed pod volumes in OADP-1.2

Description of problem:

When there is a completed pod that mounted volumes in a namespace covered by restic (podvolumebackup) velero backup, backup will not complete successfully.

Occurs when defaultVolumesToFsBackup is `true`

OADP-1075 contain info on documentation based workaround which applies when OADP-1870 is not yet resolved.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Create a pod that runs to completion and has volumeMounts
2. Create velero restic backup

Actual results:

 PodVolumeBackup fails

Expected results:

 Backup complete successfully

Additional info: