1. Set enablePSP to false by default
1. Bump K8s min version support and CSI sidecar versions
* Min Kubernetes version from 1.18 to 1.21
* longhornio/csi-resizer v1.2.0 -> v1.3.0
* longhornio/csi-snapshotter: v3.0.3 -> v5.0.1
1. Update CSI snapshot examples from v1beta1 to v1
1. Updating images file
1. Gnerating new longhorn.yaml from the chart for kubectl
Longhorn-4003
Longhorn-4239
Signed-off-by: Phan Le <phan.le@suse.com>