Cleanup: fix some CSS comment styles (especially copyrights)

chrome/browser/resources/chromeos/login/navigation_bar.css

 /* Copyright 2015 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
+ * found in the LICENSE file. */
 
 :host {
   display: block;
   height: calc(2 * 10px + 24px); /* Buttons' height is 24px. */
   min-width: 100px;
   position: relative;
 }
 
 gaia-icon-button {
   margin: 0 10px;
 }
 
 :host-context(html[dir='rtl']) #backButton {
   transform: scaleX(-1);
 }