Please update the quickstart guide with an example using google-auth-library-java

**Problem**
The example in the quickstart guide '[Running a Search Console App in Java](https://developers.google.com/webmaster-tools/search-console-api-original/v3/quickstart/quickstart-java)' is still using the deprecated googleapis.auth.oauth2.GoogleCredential. I understand that googleapis.google-auth-library-java.credentials should be used instead.

**Solution**
I'd like to see an updated example in the quickstart-guide where the google-auth-library-java is used.

**Additional context**
I've asked this question on several places, but nobody seems to be able to come up with an example.

Comece pelo guia de início rápido vinculado “Running a Search Console App in Java” e inspecione como o exemplo de autenticação usa o GoogleCredential obsoleto. Atualize o guia com um exemplo que use google-auth-library-java e confirme que o exemplo resultante demonstra claramente a substituição solicitada.

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