title: Biometric Prompt crashing on Android 9 and 10 on some devices
body: <p>I am using BiometricPrompt to let the user use fingerprint authentication to log into the app
  I have done the following in my PasswordActivity class:</p>
  
  <pre><code>     Executor executor = Executors.newSingleThreadExecutor();
  
      FragmentActivity activity = this;
  
      final BiometricPrompt biometricPrompt = new BiometricPrompt(activity, executor, new BiometricPrompt.AuthenticationCallback() {
          @Override
          public void onAuthenticationError(int errorCode, @NonNull CharSequence errString) {
              super.onAuthenticationError(errorCode, errString);
              if (errorCode == BiometricPrompt.ERROR_NEGATIVE_BUTTON) {
                  // user clicked negative button
              } else {
                  //TODO: Called when an unrecoverable error has been encountered and the operation is complete.
              }
          }
  
          @Override
          public void onAuthenticationSucceeded(@NonNull BiometricPrompt.AuthenticationResult result) {
              super.onAuthenticationSucceeded(result);
              //TODO: Called when a biometric is recognized.
              final String decryptedText = decryptText();
              runOnUiThread(new Runnable() {
                  @Override
                  public void run() {
                      if (decryptedText != null &amp;&amp; !decryptedText.isEmpty()) {
                          editPassword.setText(decryptedText);
                          buttonNext();
                      }
                  }
              });
  
          }
  
          @Override
          public void onAuthenticationFailed() {
              super.onAuthenticationFailed();
              //TODO: Called when a biometric is valid but not recognized.
          }
      });
  
      final BiometricPrompt.PromptInfo promptInfo = new BiometricPrompt.PromptInfo.Builder()
              .setTitle("My App"))
              .setSubtitle("Log on into the app"))
              .setNegativeButtonText("Cancel").toUpperCase())
              .build();
  
      if (sharedPreferenceManager.isFingerprintEnabled(this))
          biometricPrompt.authenticate(promptInfo);   
  </code></pre>
  
  <p>This is the exception that I am getting. Do I have to set?</p>
  
  <pre><code>setNegativeButton (CharSequence text, 
              Executor executor, 
              DialogInterface.OnClickListener listener) as well?
  </code></pre>
  
  <p>I am using implementation 'androidx.biometric:biometric:1.0.0-alpha03' this version.</p>
  
  <pre><code>Caused by java.lang.IllegalArgumentException: Executor must not be null
     at android.hardware.biometrics.BiometricPrompt$Builder.setNegativeButton + 182(BiometricPrompt.java:182)
     at androidx.biometric.BiometricFragment.onCreate + 201(BiometricFragment.java:201)
     at androidx.fragment.app.Fragment.performCreate + 2414(Fragment.java:2414)
     at androidx.fragment.app.FragmentManagerImpl.moveToState + 1418(FragmentManagerImpl.java:1418)
     at androidx.fragment.app.FragmentManagerImpl.moveFragmentToExpectedState + 1784(FragmentManagerImpl.java:1784)
     at androidx.fragment.app.FragmentManagerImpl.moveToState + 1861(FragmentManagerImpl.java:1861)
     at androidx.fragment.app.FragmentManagerImpl.dispatchStateChange + 3269(FragmentManagerImpl.java:3269)
     at androidx.fragment.app.FragmentManagerImpl.dispatchCreate + 3223(FragmentManagerImpl.java:3223)
     at androidx.fragment.app.FragmentController.dispatchCreate + 190(FragmentController.java:190)
     at androidx.fragment.app.FragmentActivity.onCreate + 369(FragmentActivity.java:369)
     at androidx.appcompat.app.AppCompatActivity.onCreate + 85(AppCompatActivity.java:85)
  </code></pre>