Add the Cleanspec rule for product-services symlink.

Bug: 112431447
Test: `m dist` when there's a leftover symlink of "/product-services".
Change-Id: I39bb79bd7790fe2243075768c6423b0fddc379f7
diff --git a/CleanSpec.mk b/CleanSpec.mk
index 61550b8..903f0c9 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -498,6 +498,7 @@
 # Remove product-services related files / images
 $(call add-clean-step, find $(PRODUCT_OUT) -type f -name "*product-services*" -print0 | xargs -0 rm -rf)
 $(call add-clean-step, find $(PRODUCT_OUT) -type d -name "*product-services*" -print0 | xargs -0 rm -rf)
+$(call add-clean-step, find $(PRODUCT_OUT) -type l -name "*product-services*" -print0 | xargs -0 rm -rf)
 
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST