Change `test_can_request_each_observation_individually` to include actions. Although actions in StepRequests are optional, an env impl can return an error if mandatory for itself (ex: can't skip your turn at chess & can't have a default action).
Change `test_can_request_each_observation_individually` to include actions. Although actions in StepRequests are optional, an env impl can return an error if mandatory for itself (ex: can't skip your turn at chess & can't have a default action).

PiperOrigin-RevId: 407582057
Change-Id: I854b6476b4713ef955ac0f2f0e809cafc875aff4

deepmind/dm_env_rpc