<FrameLayout 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"
             tools:context=".MainActivity"
             android:orientation="vertical"
    >

  <Button
      android:text="@string/launch_map_picker"
      android:id="@+id/map_button"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:padding="24dp"
      android:layout_gravity="center"
      />
</FrameLayout>

<FrameLayout 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"
             tools:context=".MainActivity"
    >

  <Button
      android:text="@string/launch_map_picker"
      android:id="@+id/map_button"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:padding="24dp"
      android:layout_gravity="center"
      />
</FrameLayout>

Remove unneeded orientation in a FrameLayout
Remove unneeded orientation in a FrameLayout