App Icon doesnt show up in Actionbar (Android Stuiod 1.0.1)

So I'm pretty new to android development and I just can't get ANY icon to show up in the actionbar.

I create a new project with minimum sdk API 15 and choose "Holo.Light" in the Theme-Dropdown (XML-Design-View).

So I want it to look like this: http://i.stack.imgur.com/zfgCq.png

but instead it looks like this: http://i.imgur.com/Lmxutct.png

My AndroidManifest.xml:

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

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

I guess I have to change android:theme to Holo.Light somehow? but theres no ressource defined and I cant seem to add any..

my styles.xml:

<resources>

<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"/>
    <!-- Customize your theme here. -->

The ic_launcher.png is in the drawables folder.. so what do I have to do to get that damn icon to show up?

(I use my HTC one M8 btw, but it doesnt show up on an emulator either)

thanks!