Linter - adding x-ms-enum type for enum (#18190)

Co-authored-by: Mita Garg <[email protected]>

Author: mitagarg

specification/cost-management/resource-manager/Microsoft.CostManagement/stable/2021-10-01/costmanagement.json

@@ -1445,7 +1445,11 @@
           "enum": [
             "Ascending",
             "Descending"
-          ]
+          ],
+          "x-ms-enum": {
+            "name": "ReportConfigSortingType",
+            "modelAsString": true
+          }
         },
         "name": {
           "description": "The name of the column to sort.",