network create should use firewall plugin

when creating a network, podman should add the firewall plugin to the config but not specify a backend.  this will allow cni to determine whether it should use an iptables|firewalld backend.

Signed-off-by: Brent Baude <bbaude@redhat.com>

pkg/adapter/network.go

@@ -209,6 +209,7 @@ func (r *LocalRuntime) NetworkCreateBridge(cli *cliconfig.NetworkCreateValues) (
 	bridge := network.NewHostLocalBridge(bridgeDeviceName, isGateway, false, ipMasq, ipamConfig)
 	plugins = append(plugins, bridge)
 	plugins = append(plugins, network.NewPortMapPlugin())
+	plugins = append(plugins, network.NewFirewallPlugin())
 	// if we find the dnsname plugin, we add configuration for it
 	if network.HasDNSNamePlugin(runtimeConfig.CNIPluginDir) && !cli.DisableDNS {
 		// Note: in the future we might like to allow for dynamic domain names

pkg/network/netconflist.go

@@ -110,7 +110,6 @@ func NewPortMapPlugin() PortMapConfig {
 func NewFirewallPlugin() FirewallConfig {
 	return FirewallConfig{
 		PluginType: "firewall",
-		Backend:    "iptables",
 	}
 }