GoogleCloudEnterpriseSearchRetriever fails to where location is "us"
Labels: name: area: vector store, name: auto:bug

### System Info

'OS_NAME': 'DEBIAN_10'
Langchain version :  '0.0.288'
python :  3.10

### Who can help?

_No response_

### Information

- [ ] The official example notebooks/scripts
- [X] My own modified scripts

### Related Components

- [ ] LLMs/Chat Models
- [ ] Embedding Models
- [ ] Prompts / Prompt Templates / Prompt Selectors
- [ ] Output Parsers
- [ ] Document Loaders
- [X] Vector Stores / Retrievers
- [ ] Memory
- [ ] Agents / Agent Executors
- [ ] Tools / Toolkits
- [ ] Chains
- [ ] Callbacks/Tracing
- [ ] Async

### Reproduction

This issue only occurs when region != "global". The retriever works well when region is set to "global"

Steps to reproduce :
1. Create a Enterprise search App with region = 'us'
![BHJRUwAReLjYUxb](https://github.com/langchain-ai/langchain/assets/31382824/89dc0e15-c8ce-4d64-be4c-9087705870da)

3. Import langchain version 0.0.288
```
import langchain
from langchain.retrievers import GoogleCloudEnterpriseSearchRetriever

PROJECT_ID = "<PROJECT_ID>"  # Set to your Project ID
SEARCH_ENGINE_ID = "<SEARCH_ENGINE_ID>"#"# Set to your data store ID

retriever = GoogleCloudEnterpriseSearchRetriever(
    project_id=PROJECT_ID,
    search_engine_id=SEARCH_ENGINE_ID,
    max_documents=3 ,
    location_id = "us"
)

retriever.get_relevant_documents("What is capital of India?")
```

4. Code errors out with below
```
---------------------------------------------------------------------------
_InactiveRpcError                         Traceback (most recent call last)
File /opt/conda/envs/python310/lib/python3.10/site-packages/google/api_core/grpc_helpers.py:72, in _wrap_unary_errors.<locals>.error_remapped_callable(*args, **kwargs)
     71 try:
---> 72     return callable_(*args, **kwargs)
     73 except grpc.RpcError as exc:

File /opt/conda/envs/python310/lib/python3.10/site-packages/grpc/_channel.py:1161, in _UnaryUnaryMultiCallable.__call__(self, request, timeout, metadata, credentials, wait_for_ready, compression)
   1155 (
   1156     state,
   1157     call,
   1158 ) = self._blocking(
   1159     request, timeout, metadata, credentials, wait_for_ready, compression
   1160 )
-> 1161 return _end_unary_response_blocking(state, call, False, None)

File /opt/conda/envs/python310/lib/python3.10/site-packages/grpc/_channel.py:1004, in _end_unary_response_blocking(state, call, with_call, deadline)
   1003 else:
-> 1004     raise _InactiveRpcError(state)

_InactiveRpcError: <_InactiveRpcError of RPC that terminated with:
	status = StatusCode.NOT_FOUND
	details = "DataStore projects/PROJECT_ID/locations/us/collections/default_collection/dataStores/SEARCH_ENGINE_ID not found."
	debug_error_string = "UNKNOWN:Error received from peer ipv4:172.253.120.95:443 {created_time:"2023-09-14T12:55:00.327037809+00:00", grpc_status:5, grpc_message:"DataStore projects/PROJECT_ID/locations/us/collections/default_collection/dataStores/SEARCH_ENGINE_ID not found."}"
>

The above exception was the direct cause of the following exception:

NotFound                                  Traceback (most recent call last)
Cell In[365], line 1
----> 1 retriever.get_relevant_documents("What is capital of India?")

File ~/.local/lib/python3.10/site-packages/langchain/schema/retriever.py:208, in BaseRetriever.get_relevant_documents(self, query, callbacks, tags, metadata, **kwargs)
    206 except Exception as e:
    207     run_manager.on_retriever_error(e)
--> 208     raise e
    209 else:
    210     run_manager.on_retriever_end(
    211         result,
    212         **kwargs,
    213     )

File ~/.local/lib/python3.10/site-packages/langchain/schema/retriever.py:201, in BaseRetriever.get_relevant_documents(self, query, callbacks, tags, metadata, **kwargs)
    199 _kwargs = kwargs if self._expects_other_args else {}
    200 if self._new_arg_supported:
--> 201     result = self._get_relevant_documents(
    202         query, run_manager=run_manager, **_kwargs
    203     )
    204 else:
    205     result = self._get_relevant_documents(query, **_kwargs)

File ~/.local/lib/python3.10/site-packages/langchain/retrievers/google_cloud_enterprise_search.py:254, in GoogleCloudEnterpriseSearchRetriever._get_relevant_documents(self, query, run_manager)
    251 search_request = self._create_search_request(query)
    253 try:
--> 254     response = self._client.search(search_request)
    255 except InvalidArgument as e:
    256     raise type(e)(
    257         e.message + " This might be due to engine_data_type not set correctly."
    258     )

File /opt/conda/envs/python310/lib/python3.10/site-packages/google/cloud/discoveryengine_v1beta/services/search_service/client.py:577, in SearchServiceClient.search(self, request, retry, timeout, metadata)
    570 metadata = tuple(metadata) + (
    571     gapic_v1.routing_header.to_grpc_metadata(
    572         (("serving_config", request.serving_config),)
    573     ),
    574 )
    576 # Send the request.
--> 577 response = rpc(
    578     request,
    579     retry=retry,
    580     timeout=timeout,
    581     metadata=metadata,
    582 )
    584 # This method is paged; wrap the response in a pager, which provides
    585 # an `__iter__` convenience method.
    586 response = pagers.SearchPager(
    587     method=rpc,
    588     request=request,
    589     response=response,
    590     metadata=metadata,
    591 )

File /opt/conda/envs/python310/lib/python3.10/site-packages/google/api_core/gapic_v1/method.py:113, in _GapicCallable.__call__(self, timeout, retry, *args, **kwargs)
    110     metadata.extend(self._metadata)
    111     kwargs["metadata"] = metadata
--> 113 return wrapped_func(*args, **kwargs)

File /opt/conda/envs/python310/lib/python3.10/site-packages/google/api_core/grpc_helpers.py:74, in _wrap_unary_errors.<locals>.error_remapped_callable(*args, **kwargs)
     72     return callable_(*args, **kwargs)
     73 except grpc.RpcError as exc:
---> 74     raise exceptions.from_grpc_error(exc) from exc

NotFound: 404 DataStore projects/PROJECT_ID/locations/us/collections/default_collection/dataStores/SEARCH_ENGINE_ID not found.
```

### Expected behavior

Code should return three relevant documents from Enterprise Search