FIX: PlayerInput.Instantiate not handling control schemes correctly.

[Rene-Damm]

User report: https://forum.unity.com/threads/playerinput-instantiate-ignores-controller-schemes-for-multiplayer-with-players-on-same-device.730868/

The following used to result in two players with both having all keyboard bindings from all control schemes active rather than one using "KeyboardWASD" only and the other using "KeyboardArrows" only. Was a problem in InputUser where the order in which actions were set on a user WRT when its control scheme was set ended up mattering when it shouldn't.

PlayerInput.Instantiate(player, controlScheme: "Keyboard WASD", pairWithDevice: Keyboard.current);
PlayerInput.Instantiate(player, controlScheme: "Keyboard Arrows", pairWithDevice: Keyboard.current);