Black screen when using zxing embedded for android (Java)

I'm trying to follow the example showed in the zxing page in GitHub for a continuous QRCode scanner. The problem is that when i run the project on my device, all i got is a black screen instead of the preview of my phone camera. Below is my code in SelecionarArduinoActivity.java:

public class SelecionarArduinoActivity extends AppCompatActivity {

    private SelecionarArduinoController controller;
    private DecoratedBarcodeView barcodeView;
    private BeepManager beepManager;
    private String lastText;

    private BarcodeCallback callback = new BarcodeCallback() {
        @Override
        public void barcodeResult(BarcodeResult result) {
            if(result.getText() == null || result.getText().equals(lastText)){
                return;
            }

            lastText = result.getText();
            barcodeView.setStatusText(result.getText());
            beepManager.playBeepSoundAndVibrate();
            ImageView imageView = findViewById(R.id.barcodePreview);
            imageView.setImageBitmap(result.getBitmapWithResultPoints(Color.YELLOW));
        }

        @Override
        public void possibleResultPoints(List<ResultPoint> resultPoints) {
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_selecionar_arduino);
        barcodeView = findViewById(R.id.barcode_scanner);
        Collection<BarcodeFormat> formats = Arrays.asList(BarcodeFormat.QR_CODE);
        barcodeView.getBarcodeView().setDecoderFactory(new DefaultDecoderFactory(formats));
        barcodeView.initializeFromIntent(getIntent());
        barcodeView.decodeContinuous(callback);

        beepManager = new BeepManager(this);
        controller = new SelecionarArduinoController(SelecionarArduinoActivity.this);
    }

And for my layout in xml i got:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <com.journeyapps.barcodescanner.DecoratedBarcodeView
        android:id="@+id/barcode_scanner"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_above="@+id/buttonsLayout"
        android:layout_alignParentTop="true">

    </com.journeyapps.barcodescanner.DecoratedBarcodeView>

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:id="@+id/buttonsLayout"
        android:layout_toLeftOf="@+id/centerHorizont">

        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Pause"
            />

        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Resume"
            />
    </LinearLayout>

    <View
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_centerHorizontal="true"
        android:id="@+id/centerHorizont" />

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/centerHorizont"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_alignTop="@id/buttonsLayout"
        android:id="@+id/barcodePreview" />

</RelativeLayout>

At this point, please this ignore the buttons of pause and resume, i got it for the example, but i'm not going to use it.

And finally, my Logcat result:

03/11 18:42:19: Launching 'app' on Xiaomi Mi A3.
$ adb shell am start -n "br.usp.ardhouse/br.usp.ardhouse.activity.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Connected to process 13138 on device 'xiaomi-mi_a3-d0c96fd050b8'.
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
I/Perf: Connecting to perf service.
E/Perf: Fail to get file list br.usp.ardhouse
    getFolderSize() : Exception_1 = java.lang.NullPointerException: Attempt to get length of null array
E/Perf: Fail to get file list br.usp.ardhouse
    getFolderSize() : Exception_1 = java.lang.NullPointerException: Attempt to get length of null array
W/br.usp.ardhous: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (greylist, reflection, allowed)
W/br.usp.ardhous: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (greylist, reflection, allowed)
I/AdrenoGLES: QUALCOMM build                   : 1604d02, I97efb879e3
    Build Date                       : 09/25/19
    OpenGL ES Shader Compiler Version: EV031.27.05.02
    Local Branch                     : 
    Remote Branch                    : 
    Remote Branch                    : 
    Reconstruct Branch               : 
    Build Config                     : S P 8.0.11 AArch64
I/AdrenoGLES: PFP: 0x016ee187, ME: 0x00000000
W/AdrenoUtils: <ReadGpuID_from_sysfs:194>: Failed to open /sys/class/kgsl/kgsl-3d0/gpu_model
W/AdrenoUtils: <ReadGpuID:218>: Failed to read chip ID from gpu_model. Fallback to use the GSL path
W/RenderThread: type=1400 audit(0.0:342325): avc: denied { search } for name="kgsl" dev="sysfs" ino=36975 scontext=u:r:untrusted_app:s0:c216,c256,c512,c768 tcontext=u:object_r:sysfs_kgsl:s0 tclass=dir permissive=0
W/Gralloc3: mapper 3.x is not supported
W/System: A resource failed to call close. 
W/ActivityThread: handleWindowVisibility: no activity for token android.os.BinderProxy@433ea66