❓👂 Question/Feedback - Deploy Application Gateway in a zone-redundant configuration

## Question/Feedback

This is about the rule of `Deploy Application Gateway in a zone-redundant configuration`.

https://learn.microsoft.com/azure/well-architected/services/networking/azure-application-gateway#reliability

Regarding this article, it says the following things.

> After you deploy a new gateway by using the Azure portal, the portal or other tooling might indicate that the gateway isn't zone-redundant. However, if the gateway is deployed in a region that supports availability zones, it's guaranteed to be zone-redundant.

> we recommend that you omit the zone list so that your gateway can use all of the availability zones, unless you have a specific reason not to use a specific zone.

So, I think current [KQL](
https://github.com/Azure/Azure-Proactive-Resiliency-Library-v2/blob/f4283b90c6cb2705fe7cc73baffdf053d729a96f/azure-resources/Network/applicationGateways/kql/c9c00f2a-3888-714b-a72b-b4c9e8fcffb2.kql#L6) is incorrect.
`isnull(zones)` is unnecessary anymore.

## Possible Answers/Solutions?

- Recheck the current behavior of Application Gateway
- Update the KQL if needed