CollapsingToolbar - Activity title covers tabs

I've already facing this problem:

Title of MainActivity is veiling the tabs. Could you tell me how to change positions of it?

Here is an XML code:

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appbar"
        android:layout_width="match_parent"
        android:layout_height="256dp"
        android:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar">

        <android.support.design.widget.CollapsingToolbarLayout
            android:id="@+id/collapsing_toolbar"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_scrollFlags="scroll|exitUntilCollapsed"
            android:textAlignment="gravity"
            android:layout_gravity="center"
            android:foregroundGravity="center">

            <android.support.design.widget.TabLayout
                android:id="@+id/tabs"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:layout_gravity="bottom"
                app:tabContentStart="72dp"
                app:tabMode="scrollable"
                tools:background="@android:color/holo_orange_light"/>

            <android.support.v7.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="?attr/actionBarSize"
                android:background="?attr/colorPrimary"
                app:layout_collapseMode="parallax"
                app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
                tools:background="@android:color/holo_green_light"/>

        </android.support.design.widget.CollapsingToolbarLayout>

    </android.support.design.widget.AppBarLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_marginTop="20dp"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        tools:background="@android:color/holo_blue_light"/>

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end|bottom"
        android:layout_margin="8dp"
        android:src="@drawable/ic_action_add_issue"
        app:borderWidth="0dp"
        app:fabSize="mini"
        app:layout_anchor="@id/tabs"
        app:layout_anchorGravity="center|left|start"
        tools:background="@android:color/holo_green_light"/>


</android.support.design.widget.CoordinatorLayout>