Set hdf var 'dac' to true in droiddoc options.
Allows for DAC template customizations in Doclava.

Test: make offline-sdk-docs
Change-Id: I11aa79eeba2f7440fa68ee92276eecec6db7f836
diff --git a/Android.mk b/Android.mk
index 6d797ace..aecfda4 100644
--- a/Android.mk
+++ b/Android.mk
@@ -981,6 +981,7 @@
 framework_docs_SDK_REL_ID:=1
 
 framework_docs_LOCAL_DROIDDOC_OPTIONS += \
+		-hdf dac true \
 		-hdf sdk.codename N \
 		-hdf sdk.preview.version 5 \
 		-hdf sdk.version $(framework_docs_SDK_VERSION) \