adding comment about setting ro.build.display.id twice

BUILD_KEYS := dev-keys

endif

#BUILD_DISPLAY_KEYS is used in etc/build.prop and product build.prop to avoid override by vendor, 

#so ro.build.display.id will be set twice, only product build.prop will be used at the end

ifndef RELEASE_TYPE

  BUILD_DISPLAY_KEYS := $(BUILD_KEYS)

else