Allow at most one guest network with null tag in Zone creation wizard

Author: vishesh92

ui/src/views/infra/zone/ZoneWizardPhysicalNetworkSetupStep.vue

@@ -453,6 +453,7 @@ export default {
       }
       const shouldHaveLabels = physicalNetworks.length > 1
       let isValid = true
+      let guestTrafficNullCount = 0
       this.requiredTrafficTypes.forEach(type => {
         if (!isValid) return false
         let foundType = false
@@ -462,13 +463,20 @@ export default {
             if (traffic.type === type) {
               foundType = true
             }
+            if (traffic.type === 'guest' && type === 'guest' && (!traffic.label || traffic.label.length === 0)) {
+              guestTrafficNullCount++
+            }
             if (this.hypervisor !== 'VMware') {
               if (shouldHaveLabels && (!traffic.label || traffic.label.length === 0)) {
-                isValid = false
+                if (!(traffic.type === 'guest' && foundType && guestTrafficNullCount <= 1)) {
+                  isValid = false
+                }
               }
             } else {
               if (shouldHaveLabels && (!traffic.vSwitchName || traffic.vSwitchName.length === 0)) {
-                isValid = false
+                if (!(traffic.type === 'guest' && foundType && guestTrafficNullCount <= 1)) {
+                  isValid = false
+                }
               }
             }
           })