space-android/res/drawable/fab_label_background.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="@color/black_semi_transparent"/>
    <padding
        android:left="@dimen/standard_padding"
        android:top="4dp"
        android:right="@dimen/standard_padding"
        android:bottom="4dp"/>
    <corners
        android:radius="2dp"/>
</shape>