title: Jack compiler seems to ignore encoding compile option
body: <p>I recently upgraded an Android project to use use the Jack compiler:</p>
  
  <pre><code>jackOptions {
    enabled true
  }
  </code></pre>
  
  <p>It uses box-drawing characters that are embedded in source files as string literals.  Everything was fine pre-Jack.  I used:</p>
  
  <pre><code>compileOptions {
    encoding "UTF-8"
    // {snip}
  }
  </code></pre>
  
  <p>and the box drawing characters appeared at runtime.  After upgrading to Jack, it renders as corrupted Unicode-interpreted-as-ASCII (?): <strong>â”,</strong> instead of <strong>│</strong></p>
  
  <p>I can work around this by using Unicode escapes (<strong>\u2502</strong>), but it's a bit odd that a brand new compiler for Java doesn't support Unicode...  Is there another option that Jack recognizes to accept UTF-8 encoded source files?</p>