Fix CleanSpec.mk diff

Add a line to match the last AOSP line, to make
auto-merging between the two possible.

Test: No
Change-Id: If3a7130efcf14f19decd48cfa25fe8ef22dc52b8
diff --git a/CleanSpec.mk b/CleanSpec.mk
index 21331f5..642333b 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -682,6 +682,8 @@
 # Change file layout of system_other
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system_other)
 
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/apex)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************