title: What is the most efficient way to convert a .XLS to Google Sheets in App Script?
body: <p>I download a .XLS file automatically to a Google drive weekly.
  I would like to automatically convert the latest downloaded .XLS file every week to Google sheets format.</p>
  
  <p>Thus go to specific Google drive folder. Find the latest or unconverted .XLS file. Convert to Google sheets format and save in the same folder.</p>