Just to add to the other answers, I found that the simplest solution to achieve the rounded corners was to set the following as a background to your Edittext.
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
<solid android:color="@android:color/white"/>
<corners android:radius="8dp"/>
</shape>