title: The CryptoObject in BiometricPrompt.AuthenticationResult is always null
body: <p>I am using biometric authentication dialog but my cryptoObject is always null.
  I have a fragment but I also tried directly from the activity. </p>
  
  <p>Here is my code,</p>
  
  <p>private Handler biometricPromptHandler = new Handler();</p>
  
  <pre><code>private Executor executor = command -&gt; biometricPromptHandler.post(command);
  private void showBiometricPrompt( String title, String description,
                                   BiometricsCompatCallback compatCallback) {
  
      BiometricPrompt.PromptInfo promptInfo =
              new BiometricPrompt.PromptInfo.Builder()
                      .setTitle(title)
                      .setSubtitle(description)
                      .setNegativeButtonText("Cancel")
                      .build();
  
      BiometricPrompt biometricPrompt = new BiometricPrompt((FragmentActivity) context,
              executor, new BiometricPrompt.AuthenticationCallback() {
          @Override
          public void onAuthenticationError(int errorCode,
                                            @NonNull CharSequence errString) {
              super.onAuthenticationError(errorCode, errString);
              compatCallback.onAuthenticationError(errorCode, errString);
              Log.d("onAuthenticationError", ": ");
          }
  
          @Override
          public void onAuthenticationSucceeded(
                  @NonNull BiometricPrompt.AuthenticationResult result) {
              super.onAuthenticationSucceeded(result);
              Log.d("result", ": "+(result.getCryptoObject()));
              BiometricPrompt.CryptoObject authenticatedCryptoObject =
                      result.getCryptoObject();
              Log.d("onAuthentionSucceeded", ": "+(authenticatedCryptoObject==null));
              if (authenticatedCryptoObject != null) {
                   cipher = authenticatedCryptoObject.getCipher();
                  Log.d("onAuthentionSucceeded", ": ");
                  compatCallback.onAuthenticationSuccessful(cipher);
              }else {
                  Log.d("cipher", "onAuthenticationSucceeded: ");
              }
  
          }
  
          @Override
          public void onAuthenticationFailed() {
              Log.d("onAuthenticationFailed", ": ");
              super.onAuthenticationFailed();
              compatCallback.onAuthenticationFailed();
          }
      });
  
  
          biometricPrompt.authenticate(promptInfo);
  
  
  
  }
  </code></pre>
  
  <p>Anybody knows what I am doing wrong?</p>