Featurestore entity read fails with AttributeError: _pb

#### Environment details

- OS type and version: `OSX 14.2.1`
- Python version: `Python 3.11.7`
- pip version: `pip 23.3.2`
- `google-cloud-aiplatform` version: ` 1.40.0`

#### Code example

```python
fs = aiplatform.Featurestore(
"projects/my-project"
"/locations/europe-west1"
"/featurestores/my-feature-store"
)
entity = fs.get_entity_type(entity_type_id="my-entity")
entity.read(entity_ids="1")
```

#### Stack trace
```
AttributeError Traceback (most recent call last)
Cell In[20], [line 1](vscode-notebook-cell:?execution_count=20&line=1)
----> [1](vscode-notebook-cell:?execution_count=20&line=1) entity.read(entity_ids="1")

File [/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1496](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1496), in _EntityType.read(self, entity_ids, feature_ids, request_metadata, read_request_timeout)
[1487](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1487) entity_views = [
[1488](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1488) response.entity_view
[1489](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1489) for response in streaming_read_feature_values_responses[1:]
[1490](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1490) ]
[1492](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1492) feature_ids = [
[1493](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1493) feature_descriptor.id for feature_descriptor in header.feature_descriptors
[1494](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1494) ]
-> [1496](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1496) return self._construct_dataframe(
[1497](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1497) feature_ids=feature_ids,
[1498](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1498) entity_views=entity_views,
[1499](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1499) )

File [/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1541](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1541), in _EntityType._construct_dataframe(feature_ids, entity_views)
[1539](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1539) entity_data = {"entity_id": entity_view.entity_id}
[1540](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1540) for feature_id, feature_data in zip(feature_ids, entity_view.data):
-> [1541](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1541) if feature_data._pb.HasField("value"):
[1542](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1542) value_type = feature_data.value._pb.WhichOneof("value")
[1543](https://file+.vscode-resource.vscode-cdn.net/opt/homebrew/anaconda3/envs/vertex/lib/python3.11/site-packages/google/cloud/aiplatform/featurestore/_entity_type.py:1543) feature_value = getattr(feature_data.value, value_type)

AttributeError: _pb
```

Making sure to follow these steps will guarantee the quickest resolution possible.

Thanks!