session-android/res/drawable/conversation_home_touch_highlight.xml

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    android:color="?attr/colorControlHighlight">
    <!-- Add half of the medium_profile_picture_size padding on the right to better work with the group icons. -->
    <item
        android:id="@android:id/mask"
        android:right="24dp">
        <shape>
            <corners
                android:bottomLeftRadius="@dimen/medium_profile_picture_size"
                android:topLeftRadius="@dimen/medium_profile_picture_size" />
            <solid android:color="@android:color/white" />
        </shape>
    </item>
</ripple>