[Android] Compile all cpp files in a folder with Android.mk

Just use shell find command to list all the cpp files and add these files to the LOCAL_SRC_FILES.

SOURCE_FILES := $(shell find $(LOCAL_PATH)/Classes/* -type f -name *.cpp)
LOCAL_SRC_FILES += $(SOURCE_FILES:$(LOCAL_PATH)/%=%)

Also this is just a example, you also can append filters such as *.cc *.h and so on.