fix wrong update for s360 (#23560)

Author: xiaoxuqi-ms

specification/mysql/resource-manager/Microsoft.DBforMySQL/FlexibleServers/preview/2021-12-01-preview/FlexibleServers.json

@@ -584,8 +584,7 @@
       "x-ms-enum": {
         "name": "EnableStatusEnum",
         "modelAsString": true
-      },
-      "default": "Disabled"
+      }
     },
     "ReplicationRole": {
       "type": "string",
@@ -598,8 +597,7 @@
         "name": "ReplicationRole",
         "modelAsString": true
       },
-      "description": "The replication role.",
-      "readOnly": true
+      "description": "The replication role."
     },
     "DataEncryption": {
       "type": "object",