Follow symlinks when using find for assets

This should have been done in
https://android-review.googlesource.com/#/c/43901/

Bug: 27954979
Change-Id: I663b5e87e0d844d37a59e404219ff5e7e364df74

core/definitions.mk

@@ -402,7 +402,7 @@ endef
 
 define find-subdir-assets
 $(sort $(if $(1),$(patsubst ./%,%, \
-	$(shell if [ -d $(1) ] ; then cd $(1) ; find ./ -not -name '.*' -and -type f -and -not -type l ; fi)), \
+	$(shell if [ -d $(1) ] ; then cd $(1) ; find -L ./ -not -name '.*' -and -type f ; fi)), \
 	$(warning Empty argument supplied to find-subdir-assets) \
 ))
 endef