When a Java client is generated using the google-api-client library, then the version used is quite old:

Any reason why we are not using something newer?

        <google-api-client-version>1.30.2</google-api-client-version>

Version 1.23.0 is from "Oct, 2017"
https://mvnrepository.com/artifact/com.google.api-client/google-api-client