title: Creating a directory in /sdcard fails
body: <p>I have been trying to create a directory in <code>/sdcard</code> programmatically, but it's not working.  The code below always outputs <code>directory not created.</code></p>
  
  <pre><code>boolean success = (new File("/sdcard/map")).mkdir(); 
  if (!success) {
      Log.i("directory not created", "directory not created");
  } else {
      Log.i("directory created", "directory created");
  }
  </code></pre>