Android center custom view in actionbar

Trying to set a custom view for my actionbar, but have the problem that it doesn't fill up the entire width of the actionbar which makes it har for me to center objects. How can i set a custom view in my actionbar that fills up the entire actionbar?

Code for setting up my actionbar:

actionBar.setDisplayShowHomeEnabled(false);
actionBar.setDisplayShowCustomEnabled(true);
actionBar.setDisplayShowTitleEnabled(false);

LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
actionBar.setCustomView(inflater.inflate(R.layout.actionbar_layout, null));

And my actionbar_layout.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:background="#EDEDED">

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/title"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:textColor="#FFFFFF"
    android:text="Testing"/>
</RelativeLayout>