storaged: 'Create new logical volume' is a button and should look like one
storaged: 'Create new logical volume' is a button and should look like one

All other cards have also buttons in the actions that look like
buttons.

In addition pficon classes don't take effect on PF4 only pages, so
remove that from the button.

cockpit-project/cockpit,martinpitt/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,mvollmer/cockpit,mvollmer/cockpit,mvollmer/cockpit,martinpitt/cockpit,mvollmer/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,mvollmer/cockpit