code: public static Intent createGetContentIntent() {
          // Implicitly allow the user to select a particular kind of data
          final Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
          // The MIME data type filter
          intent.setType("*/*");
          // Only return URIs that can be opened with ContentResolver
          intent.addCategory(Intent.CATEGORY_OPENABLE);
          return intent;
      }
docs: Get the Intent for selecting content to be used in an Intent Chooser.
  
  @return The intent for opening a file with Intent.createChooser()
  @author paulburke