Android Shape: Circle with cross(plus)
I accomplished something similar (a solid circle with a white plus in the middle) using this drawable xml:
<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item>
<shape android:shape="oval">
<solid android:color="@color/accent"/>
</shape>
</item>
<item>
<shape android:shape="line">
<stroke android:width="5dp" android:color="@android:color/white" />
</shape>
</item>
<item>
<rotate
android:fromDegrees="90"
android:pivotX="50%"
android:pivotY="50%"
android:toDegrees="-90">
<shape android:shape="line">
<stroke android:width="5dp" android:color="@android:color/white" />
</shape>
</rotate>
</item>
</layer-list>