title: int variable does not save with screen rotation
body: <p>I put an imageview to load an image of a url, it is when I click on a button it passes to the next url, thus changing the image.
  the problem is that when I rotate the screen it returns to the first image displayed.
  I tried to do an if with incremented counter but it deletes the variable and returns to the first one again.
  someone knows how to save the value of the "next" variable so when the screen rotates it keeps the value saved, or knows another way to keep the last image saved.
  api picasso</p>
  
  <p>code complete</p>
  
  <pre><code>private SmartImageView smartImage;
  
  private Button btn;
  private int proxima = 0;
  
  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_redacao_nota_1000);
  
       if (proxima == 0) {
           smartImage = (SmartImageView) findViewById(R.id.meuSmartImage);
           smartImage.setImageUrl("http://gabrielmartins70.000webhostapp.com/bao.png");
           proxima++;
  
       }
  
      btn = (Button) findViewById(R.id.button18);
      btn.setOnClickListener(new View.OnClickListener() {
  
          @Override
          public void onClick(View v) {
              // TODO Auto-generated method stub
              if (proxima == 1) {
                  smartImage.setImageUrl("http://gabrielmartins70.000webhostapp.com/2.png");
              }
          }
      });
  
  
  }}
  </code></pre>