Update mlz.portal.json (Azure#1058)

Updated "azureGateSubnetAddressPrefix" in bicep/form/mlz.portal.json to say "azureGatewaySubnetAddressPrefix".  This enables users to deploy the template spec with other than default Gateway subnet settings, because it will error out otherwise, since the deployment will use the mlz.json setting for the Gateway Subnet and the mlz.portal.json entry won't match.

src/bicep/form/mlz.portal.json

@@ -1265,7 +1265,7 @@
       "subscriptionId": "[steps('basics').hubSection.hubSubscriptionId]",
       "parameters": {
         "bastionHostSubnetAddressPrefix": "[steps('remoteAccess').azureBastionSection.bastionSubnetAddressCidrRange]",
-        "azureGateSubnetAddressPrefix": "[steps('remoteAccess').azureGatewaySubnetSection.azureGatewaySubnetAddressCidrRange]",
+        "azureGatewaySubnetAddressPrefix": "[steps('remoteAccess').azureGatewaySubnetSection.azureGatewaySubnetAddressCidrRange]",
         "defenderSkuTier": "[if(steps('compliance').defenderSection.deployDefender, 'Standard', 'Free')]",
         "deployDefenderPlans": "[steps('compliance').defenderSection.deployDefenderPlans]",
         "deployIdentity": "[steps('basics').identitySection.deployIdentity]",
@@ -1307,4 +1307,4 @@
       }
     }
   }
-}
+}