I am trying to call Google Cloud DocumentAI through a google service account. I have the json key that was generated for it and I load it into my application via the FixedCredentialsProvider and a GoogleCredentials object since it's not possible to load it via environment variables for my use case. This method used to work but now it throws an UNAUTHORIZED exception and something related to not having valid OAuth2 tokens. When I test the scenario using the GOOGLE_APPLICATION_CREDENTIALS env variable it works fine. Has there been a change that doesn't allow the FixedCredentials method anymore? I have not updated the sdk, it just stopped on its own. Is there a new way to load the credentials JSON key programmatically?