For reference extension builds, update book_path to reference the appropriate file location.

Change-Id: I1eab8fcde8348e7cd7efa90c5c1768b1103e5b97
diff --git a/tools/droiddoc/templates-sdk-dev/head_tag.cs b/tools/droiddoc/templates-sdk-dev/head_tag.cs
index 52674ba..7cf078a 100644
--- a/tools/droiddoc/templates-sdk-dev/head_tag.cs
+++ b/tools/droiddoc/templates-sdk-dev/head_tag.cs
@@ -83,6 +83,8 @@
           elif:(about||versions||wear||tv||auto) ?>/about<?cs
           elif:preview ?>/preview<?cs
           elif:design ?>/design<?cs
+          elif:reference.testSupport ?>/reference/android/support/test<?cs
+          elif:reference.wearableSupport ?>/reference/android/support/wearable<?cs
           elif:walkthru ?>/walkthru<?cs /if ?><?cs
         /if ?>/_book.yaml" />
     <?cs /if ?>