yinmeng-android/nim_uikit/res/drawable/bg_nim_water_drop_self.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <padding
        android:left="15dp"
        android:top="13dp"
        android:right="15dp"
        android:bottom="13dp" />

    <corners android:topRightRadius="4dp"
        android:topLeftRadius="20dp"
        android:bottomRightRadius="20dp"
        android:bottomLeftRadius="20dp"/>

    <solid android:color="#2A2A39"/>

</shape>