Adding missing cleanspec for audio file cleanup

Change-Id: I469601a2112994c466281a4959806a4179ffe245
diff --git a/CleanSpec.mk b/CleanSpec.mk
index d0aa368..d48904c 100644
--- a/CleanSpec.mk
+++ b/CleanSpec.mk
@@ -110,6 +110,7 @@
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/framework_intermediates/src/core/java/android/nfc/)
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/framework_intermediates/src/wifi/java)
 $(call add-clean-step, rm -rf $(OUT_DIR)/target/common/obj/JAVA_LIBRARIES/framework_intermediates/src/wifi/java)
+$(call add-clean-step, rm -rf $(PRODUCT_OUT)/system/media/audio/)
 # ************************************************
 # NEWER CLEAN STEPS MUST BE AT THE END OF THE LIST
 # ************************************************