nextcloud-talk-android/app/src/main/res/drawable/shape_incoming_message.xml

<?xml version="1.0" encoding="utf-8"?>
<!--
  ~ Nextcloud Talk application
  ~
  ~ @author Mario Danic
  ~ Copyright (C) 2017-2018 Mario Danic <mario@lovelyhq.com>
  ~
  ~ This program is free software: you can redistribute it and/or modify
  ~ it under the terms of the GNU General Public License as published by
  ~ the Free Software Foundation, either version 3 of the License, or
  ~ at your option) any later version.
  ~
  ~ This program is distributed in the hope that it will be useful,
  ~ but WITHOUT ANY WARRANTY; without even the implied warranty of
  ~ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  ~ GNU General Public License for more details.
  ~
  ~ You should have received a copy of the GNU General Public License
  ~ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  -->

<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="rectangle">

    <corners
        android:topLeftRadius="2dp"
        android:bottomRightRadius="@dimen/message_bubble_corners_radius"
        android:bottomLeftRadius="@dimen/message_bubble_corners_radius"
        android:topRightRadius="@dimen/message_bubble_corners_radius" />

    <solid android:color="@color/bg_message_list_incoming_bubble" />

</shape>