Create OOBE screen for Voice Interaction value proposition

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

 /* Copyright 2016 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. */
 
 #header-container {
   padding: 64px 64px 0 64px;
 }
 
 .oobe-header {
   min-height: 84px; /* 64 title + 20 subtitle */
 }
 
 #footer-container {
   padding: 44px 64px 0 64px;
 }
 
+#footer-container[noFooter] {
+  padding: 0;
+}
+
 #oobe-bottom {
   box-shadow: 0 -1px 1px rgba(0, 0, 0, 0.14);
   height: 80px;
   padding: 0;
   z-index: 1;
 }
+
+#oobe-bottom[hideShadow] {
+  box-shadow: 0 0 0 rgba(0, 0, 0, 0);
+}