activity.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <com.custom.view.CustomButton
        android:id="@+id/btnOk"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/ok"
        app:analyticsLabel="@string/analytics_ok"/>
</LinearLayout>