Add new tier and sku - Standard_Basic for Application Gateway (#21976)

* Add new tier and sku for standard_basic

* spaces

Author: amperugu

specification/network/resource-manager/Microsoft.Network/stable/2022-07-01/applicationGateway.json

@@ -1292,6 +1292,7 @@
             "WAF_Medium",
             "WAF_Large",
             "Standard_v2",
+            "Standard_Basic",
             "WAF_v2"
           ],
           "x-ms-enum": {
@@ -1306,7 +1307,8 @@
             "Standard",
             "WAF",
             "Standard_v2",
-            "WAF_v2"
+            "WAF_v2",
+            "Standard_Basic"
           ],
           "x-ms-enum": {
             "name": "ApplicationGatewayTier",