add x-ms-enum to synapse (Azure#17510)

Author: ArcturusZhang

specification/synapse/resource-manager/Microsoft.Synapse/stable/2021-06-01/sqlPool.json

@@ -1652,6 +1652,10 @@
             "enum": [
               "default"
             ],
+            "x-ms-enum": {
+              "name": "BlobAuditingPolicyName",
+              "modelAsString": false
+            },
             "x-ms-parameter-location": "method"
           }
         ],
@@ -1712,6 +1716,10 @@
             "enum": [
               "default"
             ],
+            "x-ms-enum": {
+              "name": "BlobAuditingPolicyName",
+              "modelAsString": false
+            },
             "x-ms-parameter-location": "method"
           },
           {
@@ -3779,6 +3787,10 @@
             "enum": [
               "default"
             ],
+            "x-ms-enum": {
+              "name": "BlobAuditingPolicyName",
+              "modelAsString": false
+            },
             "x-ms-parameter-location": "method"
           }
         ],
@@ -3838,6 +3850,10 @@
             "enum": [
               "default"
             ],
+            "x-ms-enum": {
+              "name": "BlobAuditingPolicyName",
+              "modelAsString": false
+            },
             "x-ms-parameter-location": "method"
           },
           {