Fish summoned on water render on their side for a single tick

The bug

Fish summoned underwater (using /summon, spawn egg or bucket) render on their side for a single tick, causing flashing. This can be more easily seen using the /tick freeze command.

To reproduce

1. Run /tick freeze.
2. Use a fish (e.g. tropical fish) spawn egg against a block underwater.
3. The fish is rendered on its side.
4. Run /tick step.
5. The fish is rendered correctly.