The current icon is the Holo Light
overflow icon.
You can override the overflow button style of the Holo Light
-theme with android:actionOverflowButtonStyle
<style name="Theme.Bloodpressure" parent="@android:style/Theme.Holo.Light">
<item name="android:actionBarStyle">@style/ActionBar.Solid.Bloodpressure</item>
/* Use Holo Dark style for the overflow icon*/
<item name="android:actionOverflowButtonStyle">@android:style/ActionBar.Holo.ActionButton.Overflow</item>
</style>