syncthing-android/src/main/res/layout/dialog_loading.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="@dimen/abc_action_bar_content_inset_material"
    android:gravity="center"
    app:theme="?alertDialogTheme">

    <ProgressBar
        android:id="@+id/progress"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginRight="@dimen/abc_action_bar_content_inset_material"
        android:layout_marginEnd="@dimen/abc_action_bar_content_inset_material" />

    <TextView
        android:id="@+id/loading_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</LinearLayout>