Issue with `ServiceAccountCreds` with `universe_domain`

[a-fellow-human]

Hello, it appears that ServiceAccountCreds doesn't seem to have an option to add a universe_domain. Importantly, this means that if you run

ServiceAccountCreds(scopes=scopes, **service_account_key)

with a service account key auto-generated by Google, the code will fail with error

TypeError: __init__() got an unexpected keyword argument 'universe_domain'

A simple workaround would be to simply remove the universe_domain line from the JSON key.

Other libraries such as google-auth already implement adding universe_domain.