title: ContentObserver does not notify on above API 17
body: <p>I have a ContentObserver on my application to check when a contact is edited, I have implemented it with the following code, it works on devices with lower android API than 17 but not 17 and higher.</p>
  
  <pre><code>observer = new MyContentObserver();
  getApplicationContext().getContentResolver().registerContentObserver(ContactsContract.Contacts.CONTENT_URI, true, observer);
  
  
  private class MyContentObserver extends ContentObserver
  {
      public MyContentObserver()
      {
          super(null);
      }
  
      @Override
      public void onChange(boolean selfChange)
      {
          super.onChange(selfChange);
          cache.clearCache();
      }
  }
  </code></pre>