XklLocal/app/src/main/res/drawable/detail_reference_flag.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#5082E6" />
    <corners android:radius="2dp" />
    <size
        android:width="4dp"
        android:height="16dp" />
</shape>