garage_opener/wear/res/round_activity_wear.xml

<?xml version="1.0" encoding="utf-8"?>

<android.support.wearable.view.BoxInsetLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_height="match_parent"
        android:layout_width="match_parent"
        android:background="@color/orange"
        android:padding="0dp">

        <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="140dp"
                android:padding="0dp"
                android:layout_gravity="center_vertical"
                android:orientation="vertical"
                app:layout_box="all">

                <ImageButton
                        android:id="@+id/openButton"
                        android:gravity="center"
                        android:layout_gravity="center"
                        android:layout_height="60dp"
                        android:layout_width="wrap_content"
                        android:layout_marginBottom="20dp"
                        android:src="@drawable/white_arrow_up"
                        android:background="@color/orange"
                        android:contentDescription="@string/openButton_desc"/>

                <ImageButton
                        android:id="@+id/closeButton"
                        android:gravity="center"
                        android:layout_gravity="center"
                        android:layout_height="60dp"
                        android:layout_width="wrap_content"
                        android:src="@drawable/white_arrow_down"
                        android:background="@color/orange"
                        android:contentDescription="@string/openButton_desc"/>
        <!-- use @null instead of @color/orange if filter is not used but beware NullPointerException -->
    </LinearLayout>
</android.support.wearable.view.BoxInsetLayout>