code: public static String formatElapsedTime(StringBuilder recycle, ReadableDuration elapsedDuration) {
          return android.text.format.DateUtils.formatElapsedTime(recycle,
              elapsedDuration.toDuration().toStandardSeconds().getSeconds());
      }
docs: Formats an elapsed time in a format like "MM:SS" or "H:MM:SS" (using a form
  suited to the current locale), similar to that used on the call-in-progress
  screen.
  
  See {@link android.text.format.DateUtils#formatElapsedTime} for full docs.
  
  @param recycle {@link StringBuilder} to recycle, or null to use a temporary one.
  @param elapsedDuration the elapsed duration