GOOGLE_APPLICATION_CREDENTIALS can't be found

Currently have to integrate Google Cloud Platform services into my app but recieving the following exception:

**W/System.err: java.io.IOException: The Application Default Credentials are not available. They are available if running in Google Compute Engine. Otherwise, the environment variable GOOGLE_APPLICATION_CREDENTIALS must be defined pointing to a file defining the credentials. See https://developers.google.com/accounts/docs/application-default-credentials for more information.
        at com.google.auth.oauth2.DefaultCredentialsProvider.getDefaultCredentials(DefaultCredentialsProvider.java:134)
W/System.err:     at com.google.auth.oauth2.GoogleCredentials.getApplicationDefault(GoogleCredentials.java:119)
        at com.google.auth.oauth2.GoogleCredentials.getApplicationDefault(GoogleCredentials.java:91)
        at com.google.api.gax.core.GoogleCredentialsProvider.getCredentials(GoogleCredentialsProvider.java:67)
        at com.google.api.gax.rpc.ClientContext.create(ClientContext.java:135)
        at com.google.cloud.speech.v1.stub.GrpcSpeechStub.create(GrpcSpeechStub.java:94)
        at com.google.cloud.speech.v1.stub.SpeechStubSettings.createStub(SpeechStubSettings.java:131)
        at com.google.cloud.speech.v1.SpeechClient.<init>(SpeechClient.java:144)
        at com.google.cloud.speech.v1.SpeechClient.create(SpeechClient.java:126)
        at com.google.cloud.speech.v1.SpeechClient.create(SpeechClient.java:118)
        at com.dno.app.ui.TranscriptFragment$1.onClick(TranscriptFragment.java:72)**

Environment variable is set:

.json file is here:

the app crashes at authImplicit() in this code block (fragment):

    transcriptBtn = getActivity().findViewById(R.id.transcript_button);
    transcriptBtn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            try (SpeechClient speechClient = SpeechClient.create()) {
                authImplicit(); // issue with Google Platform Login Authentification
                // - does not read the environment variable, and therefore cannot get access to the .json file.

                // The path to the audio file to transcribe
                String fileName = getFile().getName();

                // Reads the audio file into memory
                Path path = Paths.get(fileName);

                byte[] data = Files.readAllBytes(path);
                ByteString audioBytes = ByteString.copyFrom(data);

                // Builds the sync recognize request
                RecognitionConfig config =
                        RecognitionConfig.newBuilder()
                                .setEncoding(RecognitionConfig.AudioEncoding.FLAC)
                                .setSampleRateHertz(16000)
                                .setLanguageCode("en-US")
                                .build();
                RecognitionAudio audio = RecognitionAudio.newBuilder().setContent(audioBytes).build();

                // Performs speech recognition on the audio file
                RecognizeResponse response = speechClient.recognize(config, audio);
                List<SpeechRecognitionResult> results = response.getResultsList();

                for (SpeechRecognitionResult result : results) {
                    // There can be several alternative transcripts for a given chunk of speech. Just use the
                    // first (most likely) one here.
                    SpeechRecognitionAlternative alternative = result.getAlternativesList().get(0);
                    System.out.printf("Transcription: %s%n", alternative.getTranscript());
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    });

code for authImplicit():

 private void authImplicit() {
        // If you don't specify credentials when constructing the client, the client library will
        // look for credentials via the environment variable GOOGLE_APPLICATION_CREDENTIALS.
        Storage storage = StorageOptions.getDefaultInstance().getService();

        System.out.println("Buckets:");
        Page<Bucket> buckets = storage.list();
        for (Bucket bucket : buckets.iterateAll()) {
            System.out.println(bucket.toString());
        }
    }

I have selected a service account of the type, Owner, so I shouldn't be lacking any permissions.

EDIT (Still not working):
I tried using this example but it still doesn't work: https://stackoverflow.com/questions/55496769/the-application-default-credentials-are-not-available?rq=1

EDIT #2 (Working on server-side):
As it turns out, Google does not currently support Android for this task. Since this, I've moved the code to an ASP.NET back-end, and the code is now running smoothly.

Thank you for the assistance below.

I can understand you you've read the documentation and implemented all the steps stated here - https://cloud.google.com/storage/docs/reference/libraries#windows

1. As @John Hanley mentioned, did you check printing environmental variables ?

2. Its definitely not owner related permissions issue as the exception says
   java.io.IOException: The Application Default Credentials are not available. They are available if running in Google Compute Engine. Otherwise, the environment variable GOOGLE_APPLICATION_CREDENTIALS must be defined pointing to a file defining the credentials. See https://developers.google.com/accounts/docs/application-default-credentials for more information.

Now, to solve this, do you want to do only using environmental variables ? or other approaches are fine ?

if you are ok with other approaches, then take a look at this code

private void authImplicit() {
    
	//please give exact file name for this credentials.json
    Credentials credentials = GoogleCredentials
      .fromStream(new FileInputStream("C:\\Users\\dbgno\\Keys\\credentials.json"));
	Storage storage = StorageOptions.newBuilder().setCredentials(credentials)
      .setProjectId("Some Project").build().getService();

    System.out.println("Buckets:");
    Page<Bucket> buckets = storage.list();
    for (Bucket bucket : buckets.iterateAll()) {
        System.out.println(bucket.toString());
    }
}

Edit 1: working towards solution
Try this and see if you can read the JSON file that you are giving as input. The print statement should show the service account using which you are aiming to authenticate

    public static Credential getDriveService(String fileLocation, String servAccAdmin)
      throws IOException {
    HttpTransport httpTransport = new NetHttpTransport();
    JsonFactory jsonFactory = new JacksonFactory();

    GoogleCredential googleCredential =
        GoogleCredential.fromStream(new FileInputStream(fileLocation), httpTransport, jsonFactory)
            .createScoped(SCOPES);
    System.out.println("--------------- " + googleCredential.getServiceAccountId());

    Credential credential = new GoogleCredential.Builder()
        .setTransport(googleCredential.getTransport())
        .setJsonFactory(googleCredential.getJsonFactory())
        .setServiceAccountPrivateKeyId(googleCredential.getServiceAccountPrivateKeyId())
        .setServiceAccountId(googleCredential.getServiceAccountId()).setServiceAccountScopes(SCOPES)
        .setServiceAccountPrivateKey(googleCredential.getServiceAccountPrivateKey())
        .setServiceAccountUser(servAccAdmin).build();

    return credential;
}

Edit 2:

As we are seeing some credential issue, I am trying to see the way I access any other google API service, may it be drive or gmail where we manually pass the key file and build credentials, and these credentials should be used in further service calls. Now try adding these dependencies, this is just to troubleshoot by using the same way that we access google drive/gmail and etc. We will get to know if google cloud api is able to build the credential or not

<dependency>
  <groupId>com.google.http-client</groupId>
  <artifactId>google-http-client</artifactId>
  <version>${project.http.version}</version>
</dependency>
<dependency>
  <groupId>com.google.http-client</groupId>
  <artifactId>google-http-client-jackson2</artifactId>
  <version>${project.http.version}</version>
</dependency>
<dependency>
  <groupId>com.google.oauth-client</groupId>
  <artifactId>google-oauth-client-jetty</artifactId>
  <version>${project.oauth.version}</version>
</dependency>