Android makefile

在Android.mk中判断一个文件是否存在：

HAVE_TEST_CUST_FILE := $(shell test -f vendor/huaqin/resource/$(HQ_PROJECT)_$(HQ_CLIENT)/$(LOCAL_PATH)/DroidSansFallback.ttf && echo yes)  
ifeq ($(HAVE_TEST_CUST_FILE),yes)  
$(shell cp -f vendor/huaqin/resource/$(HQ_PROJECT)_$(HQ_CLIENT)/$(LOCAL_PATH)/DroidSansFallback.ttf $(PRODUCT_OUT)/system/fonts/DroidSansFallback.ttf)  
endif