hwservicemanager is not a HAL

This removes hwservicemanager from halserverdomain, because
halserverdomain is only for domains which offer a HAL service.
hwservicemanager offers HwBinder services, but those are not HAL
services.

Test: mmm system/sepolicy
Test: Device boots, no new denials.
Bug: 36494354
Bug: 36896667
Change-Id: I002e047ee1dd98f44429ab3dfe31f66dc63a8a1c