[Train] Decorate `get_device` with `PublicAPI` (#22024)
[Train] Decorate `get_device` with `PublicAPI` (#22024)

* Decorate `get_device` with `PublicAPI`

* Add documentation

* Update api.rst
ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray