How do you clean up an ArrayAdapter?

I am getting an out-of-memory condition when I use an array adapter and change screen orientation. I have made the smallest fully working code that exhibits this problem.

package com.foobar.test;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.content.Context;
import android.content.pm.ActivityInfo;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

public class TestAppActivity extends Activity {
    protected ArrayList<ListItem> mModel = new ArrayList<ListItem>();
    protected ListAdapter mAdapter = null;
    private static Context mApplicationContext = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        System.gc();
        setContentView(R.layout.main);

        if (mApplicationContext == null) { mApplicationContext = getApplicationContext(); }

        ListView lv = (ListView) findViewById(R.id.ListList);
        lv.setItemsCanFocus(true);
        mAdapter = new ListAdapter(mApplicationContext, lv, mModel);
        lv.setAdapter(mAdapter);

        if (savedInstanceState == null) {
            Log.i("test", "@@ start");
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        boolean change = true;
                        Thread.sleep(4 * 1000);
                        for (int ii = 0; ii < 200; ii++) {
                            setRequestedOrientation(change ? ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE : ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
                            Thread.sleep(4 * 1000);
                            change = !change;
                            Log.i("test", "@@ change: " + (ii+1));
                        }