mobile

I copied Noto Sinhala font (noto-sans-sinhala) to my rooted HTC one with Lollipop (Stock Rom) , it works as soon as i copied the files but when i reboot the phone (simply switch of and on) changes disappear from /system/fonts folder. By changes i meant the copied files.

Please let me know if you have any suggestion.
I'm just a newbie on the android stuff.

Boot loader unlocked using HTC Dev guide
Rooted with SuperSu using CWM touch (recovery-clockwork-touch-6.0.4.6-m7ul.img)
Fonts copied using root browser app