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

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

    <FrameLayout
        android:id="@+id/contentFrame"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior" />

    <com.google.android.material.appbar.AppBarLayout
        android:id="@+id/appBarLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:elevation="0dp"
        app:elevation="0dp">

        <code.name.monkey.appthemehelper.common.views.ATEToolbar
            android:id="@+id/toolbar"
            style="@style/Toolbar"
            app:layout_collapseMode="pin"
            app:navigationIcon="@drawable/ic_keyboard_backspace_black_24dp"
            app:titleTextAppearance="@style/ToolbarTextAppearanceNormal"
            tools:title="@string/action_settings" />

    </com.google.android.material.appbar.AppBarLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>