Raise API level to 23.

Now apps can target both MNC and 23.

Change-Id: Ife6a844dc1a12b5d37973cbb890434c950dab7aa
diff --git a/CleanSpec.mk b/CleanSpec.mk
index bfb27d9..c95ae05 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -359,6 +359,11 @@
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/app/*)
 $(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/APPS/*)
 
+# 23 is becoming alive!!!
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/build.prop)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/app/*)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/APPS/*)
+
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************