Revert AppGw HttpListeners alias change (Azure#24966)

Author: russsantos

specification/network/resource-manager/Microsoft.Network/stable/2023-04-01/applicationGateway.json

@@ -1653,11 +1653,6 @@
           "readOnly": true,
           "$ref": "./network.json#/definitions/ProvisioningState",
           "description": "The provisioning state of the frontend IP configuration resource."
-        },
-        "httpListeners": {
-          "readOnly": true,
-          "$ref": "./network.json#/definitions/SubResource",
-          "description": "Reference to the application gateway http listeners."
         }
       },
       "description": "Properties of Frontend IP configuration of an application gateway."