[BUG] AKS LZA should be compatible with Azure Landing Zones

[mosabami]

AKS reference implementation should be compatible with the ALZ (formally known as Enterprise scale landing zones) environments. We expect customers to already have ALZ deployed, so if our reference implementation doesn't work within the ALZ environment, then we are not doing this right. One of the first issues found was ALZ policies expects that all subnets have nsgs attached to them.