To replace your Samsung emoji with the Google ones. Download the Google emoji file here
Using a root explorer goto system/fonts and backup NotoColorEmoji.ttf and now replace with the one you just downloaded set the correct permissions rw-r-r. Then reboot. This will replace samsung emoji with the Google ones system wide. Just remember to backup your old one in case you want to restore.
Sent from my SM-G900F using XDA Premium 4 mobile app