[service connector ]add default value for enums (#22099)

* add default value for enums

* add default value for enum

* remove

Author: qianwens

specification/servicelinker/resource-manager/Microsoft.ServiceLinker/preview/2022-11-01-preview/servicelinker.json

@@ -1510,7 +1510,8 @@
       "x-ms-enum": {
         "name": "DeleteOrUpdateBehavior",
         "modelAsString": true
-      }
+      },
+      "default": "Default"
     },
     "ClientType": {
       "description": "The application client type",
@@ -2540,7 +2541,8 @@
       "x-ms-enum": {
         "name": "actionType",
         "modelAsString": true
-      }
+      },
+      "default": "enable"
     },
     "AllowType": {
       "description": "Whether to allow firewall rules.",
@@ -2552,7 +2554,8 @@
       "x-ms-enum": {
         "name": "allowType",
         "modelAsString": true
-      }
+      },
+      "default": "false"
     }
   },
   "parameters": {