Quelle  dialog_show_once.xml

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

    <ScrollView
        android:id="@+id/scroll_container"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@android:color/transparent">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:paddingLeft="24dp"
            android:paddingRight="24dp">

            <TextView
                android:id="@+id/message"
                style="@style/Threema.MaterialAlertDialog.Body.Style"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginTop="8dp"
                android:text="@string/flavored__safe_configure_server_explain" />

            <com.google.android.material.checkbox.MaterialCheckBox
                android:id="@+id/checkbox"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginLeft="-6dp"
                android:layout_marginTop="12dp"
                android:checked="false"
                android:enabled="true"
                android:text="@string/dont_show_again"
                android:textAppearance="@style/Threema.TextAppearance.Dialog.Body" />

        </LinearLayout>
    </ScrollView>
</LinearLayout>