Adds back special-case optimization for UpdateIncrementalStateDistribution in UniversalPoker. This was accidentally removed previously.
Adds back special-case optimization for UpdateIncrementalStateDistribution in UniversalPoker. This was accidentally removed previously.

PiperOrigin-RevId: 321604122
Change-Id: I7ce6b791b87aa3cca6243010a6c49403660d7342

deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel