Implement from_tunnel field handling in flagString

Handle from_tunnel in flagString. So that we can show from_tunnel value
to CLI output.

Signed-off-by: Yutaro Hayakawa <yutaro.hayakawa@isovalent.com>

pkg/maps/ctmap/types.go

@@ -520,6 +520,8 @@ const (
 	ProxyRedirect
 	DSR
 	FromL7LB
+	Reserved1
+	FromTunnel
 	MaxFlags
 )
 
@@ -554,6 +556,9 @@ func (c *CtEntry) flagsString() string {
 	if (c.Flags & FromL7LB) != 0 {
 		sb.WriteString("FromL7LB ")
 	}
+	if (c.Flags & FromTunnel) != 0 {
+		sb.WriteString("FromTunnel ")
+	}
 
 	unknownFlags := c.Flags
 	unknownFlags &^= MaxFlags - 1