[Q] Trying to modify framework-res.apk => no actions topic

Hello.

I'm French and live in Japan. I own a Samsung Galaxy S4 from Docomo (SC04E) in 4.4.2 who have only English, Japanese & Korean languages and I'm trying to add the French local in some system apks. (I take them from an extracted French ROM of the S4).
All is fine for a lot of them, I'd read a lot a tutorials before begun.
But When I work in the framework-res.apk, it seems to do nothing !

Explanation :
-No translation for the contextual menu in the home screen, and no translation in the lockscreen.
-I've tried to replace the "Swipe screen to unlock" message in the res/values/strings.xml (this is the only file who contain this text) and it didn't change after install (copy and replace with root explorer) in the system/framework/ dir.
-The size of the modified file is bigger in root explorer than the original one, even after reboot, so the file is the new one.
-After long time searching, I saw that the exact text in the lockscreen is "Swipe screen to unlock." whith a dot at the end, and I don't have this sentence whith a dot in any file of the decompiled framework-res.apk !!!

What I'm doing wrong ???

PS: I saw that it's possible to "overlay" the framework-res.apk (and any system apk) with a file in /vendor/overlay/ I don't have this directory.

Thanks in advance.