arcanechat-android/res/layout/dialog_progress.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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">

    <android.support.constraint.Guideline
        android:id="@+id/guidelineTop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_begin="16dp" />


    <android.support.constraint.Guideline
        android:id="@+id/guidelineStart"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_begin="16dp" />

    <android.support.constraint.Guideline
        android:id="@+id/guidelineEnd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_end="16dp" />

    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="64dp"
        android:layout_height="wrap_content"
        android:indeterminate="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toStartOf="@id/text"
        app:layout_constraintHorizontal_chainStyle="packed"
        app:layout_constraintStart_toStartOf="@id/guidelineStart"
        app:layout_constraintTop_toTopOf="@id/guidelineTop" />

    <TextView
        android:id="@+id/text"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginLeft="8dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="@id/guidelineEnd"
        app:layout_constraintHorizontal_chainStyle="packed"
        app:layout_constraintStart_toEndOf="@id/progressBar"
        app:layout_constraintTop_toTopOf="@id/guidelineTop" />

</android.support.constraint.ConstraintLayout>