This is a relatively old question, but you can just make a circle border in the drawable folder (let's assume the xml file will be called circle_border
)
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns="http://schemas.android.com/apk/res/android"
android:shape="oval">
<solid android:color="@android:color/transparent" />
<!-- If you want a padding -->
<padding android:top="4dp" android:left="4dp" android:right="4dp" android:bottom="4dp" />
<!-- If you want the circle border to have a color -->
<strong android:width="1dp" android:color="#FFFFFF" />
</shape>
Then you can use it as the background of the ImageView
<ImageView
android:background="@drawable/circle_border"
<!-- other attributes here -->
/>