[6.x] Fix "Export Everything" to properly constrain types (#21402) (#…

…21417)

Backports the following commits to 6.x:
 - Fix "Export Everything" to properly constrain types  (#21402)

src/core_plugins/kibana/server/routes/api/management/saved_objects/scroll.js

@@ -49,7 +49,7 @@ export function registerScrollForExportRoute(server) {
       const savedObjectsClient = req.getSavedObjectsClient();
       const objects = await findAll(savedObjectsClient, {
         perPage: 1000,
-        typesToInclude: req.payload.typesToInclude
+        type: req.payload.typesToInclude
       });
       const response = objects.map(hit => {
         const type = hit.type;