Conversations/src/main/res/layout-w945dp/activity_conversations.xml

<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

        <include android:id="@+id/toolbar"
            layout="@layout/toolbar" />

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent">

            <FrameLayout
                android:id="@+id/main_fragment"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1000"/>

            <FrameLayout
                android:id="@+id/secondary_fragment"
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="1618"/>
        </LinearLayout>
    </LinearLayout>
</layout>