Add templates for devsite docs builds.

Change-Id: I0bb0238326aed7d2ff931594709cb153b2587061
diff --git a/tools/droiddoc/templates-ds/header.cs b/tools/droiddoc/templates-ds/header.cs
new file mode 100644
index 0000000..e8301be
--- /dev/null
+++ b/tools/droiddoc/templates-ds/header.cs
@@ -0,0 +1,3 @@
+<?cs call:custom_masthead() ?>
+<?cs call:custom_left_nav() ?>
+