element-android/vector/src/main/res/layout/fragment_loading.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/animatedLogoImageView"
        android:layout_width="72dp"
        android:layout_height="72dp"
        android:background="@drawable/riot_animated_logo"
        android:importantForAccessibility="no"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <ProgressBar
        android:id="@+id/progressBar"
        style="@style/Widget.Vector.ProgressBar.Horizontal"
        android:layout_width="120dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="@dimen/layout_vertical_margin_big"
        android:indeterminate="true"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/animatedLogoImageView" />

</androidx.constraintlayout.widget.ConstraintLayout>