LibreTube/app/src/main/res/layout/activity_settings.xml

<LinearLayout 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:orientation="vertical">

    <com.google.android.material.appbar.MaterialToolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:navigationIcon="@drawable/ic_arrow_back"
        app:title="@string/settings" />

    <FrameLayout
        android:id="@+id/settings"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" />

</LinearLayout>