title: the ExpandableListView ignore SetSelectedChild() method
body: <p>I use the code</p>
  
  <pre><code>ExpandableListView expandListView = (ExpandableListView) findViewById(R.id.list);
  expandListView.setAdapter(adapter);
  Boolean flag = expandListView.setSelectedChild(1, 1, true);
  </code></pre>
  
  <p>but it didn't work. Nothing happened. The group didn't expand.</p>