Storage File RenameIgnoreReadOnly parameter was incorrect (Azure#16916)

Author: seanmcc-msft

specification/storage/data-plane/Microsoft.FileStorage/preview/2021-04-10/file.json

@@ -6881,7 +6881,7 @@
       "x-ms-parameter-location": "method"
     },
     "RenameIgnoreReadOnly": {
-      "name": "x-ms-file-rename-ignore-read-only",
+      "name": "x-ms-file-rename-ignore-readonly",
       "x-ms-client-name": "ignoreReadOnly",
       "in": "header",
       "required": false,