问AlertDialog未在MapsActivity中显示

EN

private void openSettingsDialog() {

    AlertDialog.Builder builder = new AlertDialog.Builder(MapsActivity.this);
    builder.setTitle("Permissões requeridas");
    builder.setMessage("Esta app precisa de permissões de GPS. Dê essas permissões nas definições.");
    builder.setPositiveButton("Definições", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
            Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
            Uri uri = Uri.fromParts("package", getPackageName(), null);
            intent.setData(uri);
            startActivityForResult(intent, 101);
        }
    });
    builder.setNegativeButton("Cancelar", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            dialog.cancel();
        }
    });
    builder.show();

}

private void requestMultiplePermissions() {
    Dexter.withActivity(this)
            .withPermissions(
                    Manifest.permission.ACCESS_FINE_LOCATION,
                    Manifest.permission.ACCESS_COARSE_LOCATION)
            .withListener(new MultiplePermissionsListener() {
                @Override
                public void onPermissionsChecked(MultiplePermissionsReport report) {
                    // check if all permissions are granted
                    if (report.areAllPermissionsGranted()) {
                        Toast.makeText(getApplicationContext(), "Todas as permissões aceites!", Toast.LENGTH_SHORT).show();
                    }

                    // check for permanent denial of any permission
                    if (report.isAnyPermissionPermanentlyDenied()) {
                        // show alert dialog navigating to Settings
                        openSettingsDialog();
                    }
                }

                @Override
                public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {
                    token.continuePermissionRequest();
                }
            }).
            withErrorListener(new PermissionRequestErrorListener() {
                @Override
                public void onError(DexterError error) {
                    Toast.makeText(getApplicationContext(), "Algum erro ocorreu! ", Toast.LENGTH_SHORT).show();
                }
            })
            .onSameThread()
            .check();
}

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        //code for getting current location
        requestMultiplePermissions();

        tvLocation = (TextView) findViewById((R.id.tv));

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this)
                .addApi(LocationServices.API)
                .build();


        Bundle extras = getIntent().getExtras();
        if (extras != null) {
            String gpslocation = extras.getString("GPSLocation");
            String[] latLng = gpslocation.split(",");
            double latitude = Double.parseDouble(latLng[0]);
            double longitude = Double.parseDouble(latLng[1]);
            LatLocation = new LatLng(latitude, longitude);
        }
    }