Cleaner approach for _is_collection_a_view (#3113)

* Fix collection fields retreival bug when Views are present in MongoDB

* fixing _is_collection_a_view function

* Update redash/query_runner/mongodb.py

Co-Authored-By: jodevsa <jodevsa@gmail.com>

* using options() instead of try/except on collstats  to detect if a collection  is a view

redash/query_runner/mongodb.py

@@ -175,11 +175,10 @@ def _merge_property_names(self, columns, document):
                   columns.append(property)
 
     def _is_collection_a_view(self, db, collection_name):
-        try:
-            db.command('collstats', collection_name)
-            return False
-        except Exception:
+        if 'viewOn' in db[collection_name].options():
             return True
+        else:
+            return False
 
     def _get_collection_fields(self, db, collection_name):
         # Since MongoDB is a document based database and each document doesn't have