'scroll | enterAlways' behaviour without using CoordinatorLayout

activity_main.xml

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

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:contentInsetRight="10dp"
        app:contentInsetEnd="10dp"
        app:popupTheme="@style/toolbarStyle"
        app:subtitleTextAppearance="@style/styleToolbarSubtitle"
        app:titleTextAppearance="@style/styleToolbarTitle"/>

    <FrameLayout
        android:id="@+id/flChatFragmentContainer"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">

        <android.support.v7.widget.RecyclerView
            android:id="@+id/rlChat"
            android:layout_width="match_parent"
            android:layout_height="match_parent"/>

        <!-- chat_header_item is to have the behaviour of 'scroll|enterAlways -->
        <include layout="@layout/chat_header_item"/>

    </FrameLayout>

</LinearLayout>