npc: Embed policyType into rule

This ensures two rules with the same rulespec but of different
policyType will end up having different keys.

Sharing the same key would prevent from provisioning the rules.

npc/rule.go

@@ -39,8 +39,9 @@ func newRuleSpec(policyType policyType, proto *string, srcHost *selectorSpec, ds
 		args = append(args, "--dport", *dstPort)
 	}
 	args = append(args, "-j", "ACCEPT")
-	args = append(args, "-m", "comment", "--comment", fmt.Sprintf("%s -> %s", srcComment, dstComment))
-	// TODO(brb) embed policyType into key
+	// NOTE: if you remove the comment bellow, then embed `policyType` into `key`.
+	// Otherwise, the rule won't be provisioned if it exists for other policy type.
+	args = append(args, "-m", "comment", "--comment", fmt.Sprintf("%s -> %s (%s)", srcComment, dstComment, policyTypeStr(policyType)))
 	key := strings.Join(args, " ")
 
 	return &ruleSpec{key, args, policyType}