main_activity.xml

<LinearLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="vertical"
  tools:context=".MyActivity">
  <Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/notify"
    android:id="@+id/wearButton"
    android:layout_gravity="center_horizontal" />
</LinearLayout>