Drowned walk jumping on incomplete blocks

Summary:
Drowned walk jumping on incomplete blocks. Incomplete blocks in this bug are all blocks whose collision is less than a full block.
Previously, the same problem was only with pressure plates MCPE-153329.

Steps to reproduce:

1. Place incomplete blocks 3 by 3 blocks.
2. Summon in the center of the drowned.
3. Summon a nearby villager.

Observed results:
Drowned move by jumping.

Expected results:
Drowned will move around incomplete blocks normally like other mobs.