I really used to like the feature and have xposed but i cant find a module to manually install it not sure why stock rom 4.2.2 doeisnt have the feature .
Also please dont recommend light flow im not a fan of the app -_-
Off the top of my head, GravityBox is the first module I can think of that might enable the LED, but that might be a bit overkill for what you're trying to do.
