docs: add css for Android Design links and add link to site header

Change-Id: I0a9469519076b1c5b9d7c121df1f2c731a08d2cb
diff --git a/tools/droiddoc/templates-sdk/assets/android-developer-docs.css b/tools/droiddoc/templates-sdk/assets/android-developer-docs.css
index 03073eb..8e9e5bb 100644
--- a/tools/droiddoc/templates-sdk/assets/android-developer-docs.css
+++ b/tools/droiddoc/templates-sdk/assets/android-developer-docs.css
@@ -706,6 +706,18 @@
   width:auto;
 }
 
+div.design-announce {
+  border-top:1px solid #33B5E5;
+  border-bottom:1px solid #33B5E5;
+  padding:5px 10px 10px 55px;
+  margin:2em 0;
+  background:url('../design/static/ico_styleguide.png') 5px 13px no-repeat;
+}
+
+div.design-announce p {
+  margin: .5em 0 0 0;
+}
+
 div.special {
   padding: .5em 1em 1em 1em;
   margin: 0 0 1em;