To include a way to restart every Longhorn components automatically with
the latest image.
1. Now `lm-update.sh` will set `imagePullPolicy: Always` for the manager
and the driver.
2. Now update-image-pull-policy.sh will update the `imagePullPolicy` for
all the running deployments and daemonsets in the `longhorn-system`
namespace, including CSI components.
Signed-off-by: Sheng Yang <sheng.yang@rancher.com>
