Adding new SKU values (Azure#16112)

* Adding new SKU values

* Fixing basic in Tier(not name)

Co-authored-by: Ishani Gupta <[email protected]>

Author: ishaniGupta27

specification/network/resource-manager/Microsoft.Network/stable/2021-03-01/azureFirewall.json

@@ -1071,7 +1071,8 @@
           "description": "Tier of an Azure Firewall.",
           "enum": [
             "Standard",
-            "Premium"
+            "Premium",
+            "Basic"
           ],
           "x-ms-enum": {
             "name": "AzureFirewallSkuTier",

specification/network/resource-manager/Microsoft.Network/stable/2021-03-01/firewallPolicy.json

@@ -1424,7 +1424,8 @@
           "description": "Tier of Firewall Policy.",
           "enum": [
             "Standard",
-            "Premium"
+            "Premium",
+            "Basic"
           ],
           "x-ms-enum": {
             "name": "FirewallPolicySkuTier",