Customize (hide) arrow from dropdown list in ActionBar

gistfile1.txt

AndroidManifest.xml:
android:theme="@style/MyAppTheme"

Styles.xml:
    <style name="MyAppTheme" parent="@style/Theme.AppCompat.Light">
        <item name="actionDropDownStyle">@style/DropDownNav.Example</item>
    </style>

    <style name="DropDownNav.Example" parent="@style/Widget.AppCompat.Light.Spinner.DropDown.ActionBar">
        <item name="android:background">@android:color/transparent</item>
    </style>