Add images to document built-in color spaces

Bug: 32984164
Test: make offline-sdk-referenceonly-docs and manual validation of output

Change-Id: I2f0e00e5a0581517bb7c535e8aee150f87ac7a6e
diff --git a/Android.mk b/Android.mk
index 552103d..514ed47 100644
--- a/Android.mk
+++ b/Android.mk
@@ -1129,7 +1129,9 @@
 		-proofread $(OUT_DOCS)/$(LOCAL_MODULE)-proofread.txt \
 		-sdkvalues $(OUT_DOCS) \
 		-hdf android.whichdoc offline \
-		-referenceonly
+		-referenceonly \
+		-resourcesdir $(LOCAL_PATH)/docs/html/reference/images/ \
+		-resourcesoutdir reference/android/images/
 
 LOCAL_DROIDDOC_CUSTOM_TEMPLATE_DIR:=build/tools/droiddoc/templates-sdk