Fixes for /dataset_collections API endpoint.

Guess this is not as utilized as the variant under /histories.

lib/galaxy/webapps/galaxy/api/dataset_collections.py

@@ -56,7 +56,8 @@ class DatasetCollectionsController(
 
     @expose_api
     def show( self, trans, instance_type, id, **kwds ):
-        dataset_collection_instance = self.__service( trans ).get(
+        dataset_collection_instance = self.__service( trans ).get_dataset_collection_instance(
+            trans,
             id=id,
             instance_type=instance_type,
         )
@@ -67,7 +68,12 @@ class DatasetCollectionsController(
         else:
             trans.status = 501
             return
-        return dictify_dataset_collection_instance( trans, dataset_collection_instance, parent )
+        return dictify_dataset_collection_instance(
+            dataset_collection_instance,
+            security=trans.security,
+            parent=parent,
+            view='element'
+        )
 
     def __service( self, trans ):
         service = trans.app.dataset_collections_service