如何让Android BottomSheetDialogFragment出现在系统/手势栏后面？

import android.app.Dialog;
import android.os.Bundle;
import androidx.annotation.NonNull;
import com.google.android.material.bottomsheet.BottomSheetDialog;
import com.google.android.material.bottomsheet.BottomSheetDialogFragment;

public class CustomBottomSheetDialogFragment extends BottomSheetDialogFragment {

    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        BottomSheetDialog dialog = (BottomSheetDialog) super.onCreateDialog(savedInstanceState);

        // 设置窗口属性，使其位于系统UI之下
        dialog.getWindow().setFlags(
            WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
            WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
        );
        dialog.getWindow().getDecorView().setSystemUiVisibility(
            View.SYSTEM_UI_FLAG_LAYOUT_STABLE
            | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
            | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
            | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
        );
        dialog.getWindow().clearFlags(WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE);

        return dialog;
    }
}