Fix issie #23116383: Include security patch level in Settings

Change-Id: I46303c064d1365781a2c8a05bd6087518afb2aec
diff --git a/CleanSpec.mk b/CleanSpec.mk
index 7778118..64d84e3 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -369,6 +369,8 @@
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/app/*)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/APPS/*)
 
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/build.prop)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************