Add clean step for SDK version change.

Change-Id: I2ea85496af49572115dbbd9a98787b1fd54adc50
diff --git a/core/cleanspec.mk b/core/cleanspec.mk
index 675c7da..1da984e 100644
--- a/core/cleanspec.mk
+++ b/core/cleanspec.mk
@@ -178,6 +178,9 @@
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/APPS/Music*)
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/jsr305_intermediates)
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/guava_intermediates)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/obj/APPS)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/*)
+$(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/APPS)
 
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST