Python调用GCS API遇403错误：无storage.objects.get访问权限

我尝试通过Python代码下载Google Cloud Storage（GCS）中的销售报告，代码如下：

import json
from httplib2 import Http
from oauth2client.client import SignedJwtAssertionCredentials
from apiclient.discovery import build

# Change these variables to fit your case
client_email = 'nameofserviceaccount.iam.gserviceaccount.com'
json_file = '/Users/xxx/Downloads/key.json'
cloud_storage_bucket = 'pubsite_prod_rev_XXXXXXX'
report_to_download = 'earnings/earnings_XXXXX.zip'
 
private_key = json.loads(open(json_file).read())['private_key']
credentials = SignedJwtAssertionCredentials(client_email, private_key,'https://www.googleapis.com/auth/devstorage.read_only')
storage = build('storage', 'v1', http=credentials.authorize(Http()))

try:
    response = storage.objects().get(bucket=cloud_storage_bucket, object=report_to_download).execute()
    print(response)
except Exception as e:
    print(f"Error: {e}")

执行后出现如下403错误：

<HttpError 403 when requesting https://storage.googleapis.com/storage/v1/b/pubsite_prod_rev_XXXXXXX/o/earnings%2Fearnings_XXXXXXX.zip?alt=json returned "nameofserviceaccount.iam.gserviceaccount.com does not have storage.objects.get access to the Google Cloud Storage object. Permission 'storage.objects.get' denied on resource (or it may not exist).". Details: "[{'message': "nameofserviceaccount.iam.gserviceaccount.com does not have storage.objects.get access to the Google Cloud Storage object. Permission 'storage.objects.get' denied on resource (or it may not exist).", 'domain': 'global', 'reason': 'forbidden'}]"> 

已排查的情况：

• 服务账号已配置Storage Admin和Storage Object Admin权限
• 尝试删除并重新创建服务账号，问题依旧
• 尝试修改应用内商品描述，问题未解决
• Cloud Storage API已启用
• 尝试移除并重新添加Storage Admin角色
• 单独为服务账号配置Storage Object Viewer角色

此前在Google Play Console设置中可正常访问API，自Google更新API访问配置方式后出现该问题。

内容的提问来源于stack exchange，提问作者greenmonkeys