Update cs file to use devsite-compatible lowercase lang ids.

Change-Id: Ie20e5977464199648fd91515ebe71c250162c0ee
diff --git a/tools/droiddoc/templates-sdk/components/masthead.cs b/tools/droiddoc/templates-sdk/components/masthead.cs
index 0d53b5b..4f3273c 100644
--- a/tools/droiddoc/templates-sdk/components/masthead.cs
+++ b/tools/droiddoc/templates-sdk/components/masthead.cs
@@ -16,24 +16,24 @@
             <ul class="nav-x col-9">
                 <li class="design">
                   <a href="<?cs var:toroot ?>design/index.html"
-                  zh-TW-lang="設計"
-                  zh-CN-lang="设计"
+                  zh-tw-lang="設計"
+                  zh-cn-lang="设计"
                   ru-lang="Проектирование"
                   ko-lang="디자인"
                   ja-lang="設計"
                   es-lang="Diseñar"               
                   >Design</a></li>
                 <li class="develop"><a href="<?cs var:toroot ?>develop/index.html"
-                  zh-TW-lang="開發"
-                  zh-CN-lang="开发"
+                  zh-tw-lang="開發"
+                  zh-cn-lang="开发"
                   ru-lang="Разработка"
                   ko-lang="개발"
                   ja-lang="開発"
                   es-lang="Desarrollar"               
                   >Develop</a></li>
                 <li class="distribute last"><a href="<?cs var:toroot ?>distribute/index.html"
-                  zh-TW-lang="發佈"
-                  zh-CN-lang="分发"
+                  zh-tw-lang="發佈"
+                  zh-cn-lang="分发"
                   ru-lang="Распространение"
                   ko-lang="배포"
                   ja-lang="配布"
@@ -72,8 +72,8 @@
                 <option value="ja">日本語</option>
                 <option value="ko">한국어</option>
                 <option value="ru">Русский</option>
-                <option value="zh-CN">中文 (中国)</option>
-                <option value="zh-TW">中文 (台灣)</option>
+                <option value="zh-cn">中文 (中国)</option>
+                <option value="zh-tw">中文 (台灣)</option>
             </select>
           </div>
         <script type="text/javascript">
@@ -153,32 +153,32 @@
                     <li class="develop">
                       <ul>
                         <li><a href="<?cs var:toroot ?>training/index.html"
-                          zh-TW-lang="訓練課程"
-                          zh-CN-lang="培训"
+                          zh-tw-lang="訓練課程"
+                          zh-cn-lang="培训"
                           ru-lang="Курсы"
                           ko-lang="교육"
                           ja-lang="トレーニング"
                           es-lang="Capacitación"               
                           >Training</a></li>
                         <li><a href="<?cs var:toroot ?>guide/components/index.html"
-                          zh-TW-lang="API 指南"
-                          zh-CN-lang="API 指南"
+                          zh-tw-lang="API 指南"
+                          zh-cn-lang="API 指南"
                           ru-lang="Руководства по API"
                           ko-lang="API 가이드"
                           ja-lang="API ガイド"
                           es-lang="Guías de la API"               
                           >API Guides</a></li>
                         <li><a href="<?cs var:toroot ?>reference/packages.html"
-                          zh-TW-lang="參考資源"
-                          zh-CN-lang="参考"
+                          zh-tw-lang="參考資源"
+                          zh-cn-lang="参考"
                           ru-lang="Справочник"
                           ko-lang="참조문서"
                           ja-lang="リファレンス"
                           es-lang="Referencia"               
                           >Reference</a></li>
                         <li><a href="<?cs var:toroot ?>tools/index.html"
-                          zh-TW-lang="相關工具"
-                          zh-CN-lang="工具"
+                          zh-tw-lang="相關工具"
+                          zh-cn-lang="工具"
                           ru-lang="Инструменты"
                           ko-lang="도구"
                           ja-lang="ツール"
@@ -220,32 +220,32 @@
         <div class="wrap">
             <ul class="nav-x col-9 develop" style="width:100%">
                 <li class="training"><a href="<?cs var:toroot ?>training/index.html"
-                  zh-TW-lang="訓練課程"
-                  zh-CN-lang="培训"
+                  zh-tw-lang="訓練課程"
+                  zh-cn-lang="培训"
                   ru-lang="Курсы"
                   ko-lang="교육"
                   ja-lang="トレーニング"
                   es-lang="Capacitación"               
                   >Training</a></li>
                 <li class="guide"><a href="<?cs var:toroot ?>guide/components/index.html"
-                  zh-TW-lang="API 指南"
-                  zh-CN-lang="API 指南"
+                  zh-tw-lang="API 指南"
+                  zh-cn-lang="API 指南"
                   ru-lang="Руководства по API"
                   ko-lang="API 가이드"
                   ja-lang="API ガイド"
                   es-lang="Guías de la API"               
                   >API Guides</a></li>
                 <li class="reference"><a href="<?cs var:toroot ?>reference/packages.html"
-                  zh-TW-lang="參考資源"
-                  zh-CN-lang="参考"
+                  zh-tw-lang="參考資源"
+                  zh-cn-lang="参考"
                   ru-lang="Справочник"
                   ko-lang="참조문서"
                   ja-lang="リファレンス"
                   es-lang="Referencia"               
                   >Reference</a></li>
                 <li class="tools"><a href="<?cs var:toroot ?>tools/index.html"
-                  zh-TW-lang="相關工具"
-                  zh-CN-lang="工具"
+                  zh-tw-lang="相關工具"
+                  zh-cn-lang="工具"
                   ru-lang="Инструменты"
                   ko-lang="도구"
                   ja-lang="ツール"