title: GridLayoutManager setSpanSizeLookup not working
body: <p>I am using GridLayoutManager with 2 cells and for some cells I want span to be one so I tried using setSpanSizeLookup but its not working. I tried returning span count 1 for all positions but still two cells are appearing instead of one.</p>
  
  <p>Following is my code</p>
  
  <pre><code>gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
          @Override
          public int getSpanSize(int position) {
              return 1;
          }
      });
      recyclerView.setLayoutManager(gridLayoutManager);
  </code></pre>
  
  <p>Any reasons why it is not working?</p>