Describe the bug

Do a migration from Rancher old UI to dashboard using https://longhorn.io/kb/how-to-migrate-longhorn-chart-installed-in-old-rancher-ui-to-the-chart-in-new-rancher-ui/, the csi-plugin doesn't update and remains with the longhornio image instead of Rancher mirrored image.

To Reproduce

Steps to reproduce the behavior:

1. Set up a cluster of Kubernetes 1.20.
2. Access old rancher UI by navigating to <your-rancher-url>/g.
3. Install Longhorn 1.0.2.
4. Create/attach some volumes. Create a few recurring snapshot/backup job that run every minutes.
5. Upgrade Longhorn to v1.2.4.
6. Migrate Longhorn to new chart in new rancher UI https://longhorn.io/kb/how-to-migrate-longhorn-chart-installed-in-old-rancher-ui-to-the-chart-in-new-rancher-ui/.
7. Check the csi plugin image

Expected behavior

The CSI plugin image should also be updated to rancher mirrored image

Log or Support bundle

Environment

• Longhorn version: v1.2.4
• Installation method (e.g. Rancher Catalog App/Helm/Kubectl): Rancher App
• Kubernetes distro (e.g. RKE/K3s/EKS/OpenShift) and version: v1.20