activity_test.xml

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
            android:id="@+id/container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:paddingLeft="@dimen/activity_horizontal_margin"
            android:paddingRight="@dimen/activity_horizontal_margin"
            android:paddingTop="@dimen/activity_vertical_margin"
            android:paddingBottom="@dimen/activity_vertical_margin"
    >

    <LinearLayout

        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <Button
            android:id="@+id/btn"
            android:gravity="center"
            android:layout_width="match_parent"
            android:layout_height="1000dip"
            android:text="@string/start_activity"/>
    </LinearLayout>
</ScrollView>