fix db names

Author: rustagir

source/fundamentals/crud/write-operations/bulk.txt

@@ -472,7 +472,7 @@ Update Operation
 ~~~~~~~~~~~~~~~~
 
 The following example shows how to use the ``bulkWrite()`` method to update
-existing documents in the ``db.people`` and ``db.objects`` collections:
+existing documents in the ``sample_db.people`` and ``sample_db.objects`` collections:
 
 .. literalinclude:: /examples/generated/ClientBulkTest.snippet.update-models.kt
    :language: kotlin