fix(sec): warn users of unsafe credential generation methods by diegomarquezp · Pull Request #2604

fix(sec): warn users of unsafe credential generation methods by diegomarquezp · Pull Request #2604 · googleapis/google-api-java-client

Unlike the efforts in the current non-deprecated auth library googleapis/google-auth-library-java#1802 and googleapis/google-auth-library-java#1798, this library is deprecated and promotes usage of google-auth-library-java.

However, we also add a comment with notice of the unsafety of the fromStream() methods, repeating the existing note of class deprecation (the GoogleCredential is already deprecated).

This library does not have subclasses for credentials (e.g. service account credentials).