Hi i need add shadow under my tab layout (like in skype). 

[![shadow_skype](https://i.stack.imgur.com/pzYK5.png)](https://i.stack.imgur.com/pzYK5.png)

My activity xml:

```
    <RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <android.support.v7.widget.Toolbar xmlns:local="http://schemas.android.com/apk/res-auto"
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:minHeight="?attr/actionBarSize"
        android:background="@color/splashGreenTop"
        local:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        local:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
    <android.support.design.widget.TabLayout
        android:id="@+id/tab_layout"
        android:layout_below="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:elevation="0dp"
        android:minHeight="?attr/actionBarSize" />
    <FrameLayout
        android:layout_width="match_parent"
        android:layout_below="@+id/tab_layout"
        android:id="@+id/tabContainer"
        android:layout_height="match_parent" />
</RelativeLayout>

```

When i add `android:elevation="10dp"` to Tablayout, shadow was added bottom and top .. I need just bottom. See image...

[![enter image description here](https://i.stack.imgur.com/q6I3F.png)](https://i.stack.imgur.com/q6I3F.png)

How can i do this ? 
Thanks in advance.