NavigationDrawer blocks other button on the activity

I'm working on the UI of my app and I'm facing a problem when I implement the Navigation Drawer. As you can see here, I have some buttons to manage my Media Player, these are not responding to my clicks when I implement the Navigation Drawer (working fine without Navigation Drawer).

I think the problem is coming from my XML file because there are no changing when I delete the implementation in Java.

Here are my XML sheets :

main_activity.xml

<RelativeLayout xmlns:android="http://ift.tt/nIICcg"
    xmlns:tools="http://ift.tt/LrGmb4"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MyActivity">

    <fragment
        android:id="@+id/fragments"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.example.ilan.myapplication.fragments.FragmentHome" >
    </fragment>


    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:text="Buffering"
        android:id="@+id/tV_Buffering"
        android:layout_alignParentTop="true"
        android:layout_alignParentEnd="true" />

    <include
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:layout_weight="1"
        layout="@layout/player_controls"
        android:layout_alignParentBottom="true"/>

    <include
        layout="@layout/navigation_drawer_main_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

Note that I put the Navigation Drawer in the end to have it to cover the all activity.

navigation_drawer_main_layout.xml

<?xml version="1.0" encoding="utf-8"?>

<android.support.v4.widget.DrawerLayout
    xmlns:android="http://ift.tt/nIICcg"
    android:id="@+id/drawer_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <FrameLayout
        android:id="@+id/content_frame"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <ListView android:id="@+id/left_drawer"
        android:layout_width="240dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:choiceMode="singleChoice"
        android:divider="@android:color/transparent"
        android:dividerHeight="0dp"
        android:background="#FFFFFF"/>
</android.support.v4.widget.DrawerLayout>

player_controls.xml

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://ift.tt/nIICcg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/blue">

        <Button
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:id="@+id/button_play_pause"
            android:layout_toStartOf="@+id/tV_Buffering"
            android:background="@drawable/bouton_play"
            android:layout_centerInParent="true"
           />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Stop"
            android:id="@+id/button_stop"
            android:layout_toRightOf="@id/button_play_pause"
            android:layout_centerInParent="true"
            android:layout_marginLeft="20dp"/>
</RelativeLayout>

Well, if anyone has any idea from where this come from it would be awesome, thanks !