I try to customize the ActionBar. Here is my attempt: 
I overlayed the background and I would like to overlay bottom border and disable drop shadow under Action Bar.
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
<item>
<bitmap
xmlns:android="http://schemas.android.com/apk/res/android"
android:src="@drawable/actionbar_bg"
android:tileMode="repeat" />
</item>
</layer>
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