Default [Q] Translation to another language

i've got one simple question.
Will be possible to add another language on stock rom?
I know there is necessary to decompile some apk from system to translate it. There will not be problem with translation for me, but i've got worries to put together again and flash it in the system. And in the other hand, i would like if someone can use it in future on own phone.
Is there a solution, maybe if i will ask for example Omar, if there is possibility to add a language?
Thanx for replies.