ImportError: cannot import name 'client_pb2' from 'google.api' - importerror

Question

import io
import os
os.environ["GOOGLE_APPLICATION_CREDENTIALS"]="ip-boundary-996e9662df4c.json"
from google.cloud import speech
I am trying to load the library required to use Google STT, but an error occurs. Here's what the error says:
Traceback (most recent call last):
File "/home/yugwon/IP_boundary/server/stt.py", line 5, in <module>
from google.cloud import speech
File "/home/yugwon/IP_boundary/venv/lib/python3.7/site-packages/google/cloud/speech/__init__.py", line 17, in <module>
from google.cloud.speech_v1 import SpeechClient
File "/home/yugwon/IP_boundary/venv/lib/python3.7/site-packages/google/cloud/speech_v1/__init__.py", line 17, in <module>
from .services.speech import SpeechClient
File "/home/yugwon/IP_boundary/venv/lib/python3.7/site-packages/google/cloud/speech_v1/services/speech/__init__.py", line 16, in <module>
from .client import SpeechClient
File "/home/yugwon/IP_boundary/venv/lib/python3.7/site-packages/google/cloud/speech_v1/services/speech/client.py", line 43, in <module>
from google.api_core import operation # type: ignore
File "/home/yugwon/IP_boundary/venv/lib/python3.7/site-packages/google/api_core/operation.py", line 45, in <module>
from google.longrunning import operations_pb2
File "/home/yugwon/IP_boundary/venv/lib/python3.7/site-packages/google/longrunning/operations_pb2.py", line 26, in <module>
from google.longrunning.operations_proto_pb2 import *
File "/home/yugwon/IP_boundary/venv/lib/python3.7/site-packages/google/longrunning/operations_proto_pb2.py", line 31, in <module>
from google.api import client_pb2 as google_dot_api_dot_client__pb2
ImportError: cannot import name 'client_pb2' from 'google.api' (/home/yugwon/IP_boundary/python-generated/google/api/__init__.py)
As a workaround for this, I tried the following, but still the same problem appeared and failed.
pip install --upgrade googleapis-common-protos
Below is my venv pip list.
Do you have any other solution?