updateDocument() throws "document_already_exists" error instead of updating existing document

Issue: The developer is encountering a "document_already_exists" error when trying to update an existing document using the `updateDocument()` function in the server SDK. Solution: The error is likely due to attempting to update a document that already exists in the database. To resolve this, ensure that the `id_dic` provided as a parameter uniquely identifies an existing document for updating, rather than creating a new one. Double-check the value of `id_dic` and verify that it corresponds to the intended document.