On Redmi 3. Smite is supposed to affect undead mobs but deal no extra damage on variants of Zombie such as Zombie, Zombie Pigman, Zombie Villager, Husk. Tested with other Android players in 1.0 beta versions.
Update by: @unknown
How to reproduce
1. Spawn in a few Husks
2. Take an out unenchanted diamond sword and a smite 5 diamond sword
3. Notice for both swords it takes 3 hits to kill a husk
Compared to the 2 hits with a smite 5 diamond sword on the Java Edition
Confirmed and added repo steps