title: "Cannot find symbol R" error after renaming package name
body: <p>After renaming my project package name (with Refactor), I got this error:</p>
  
  <pre><code>Error:(7, 44) error: cannot find symbol class R
  </code></pre>
  
  <p>All of my <code>R</code> usages are invalid. I tried to fix it manually but it doesn't work for me. <code>Invalidate chases/Restart</code> doesn't help me, either.</p>