Called from SubsystemManager when it has completed reloading all XR SDK Provider packaged subsystems.
When the Editor starts or when packages are installed or removed, the SubsystemManager searches the packages and loads all XR SDK packages that it finds. Handling this event allows the user to do work they may need after the subsystem manager loads and initializes new subsystem descriptors.
See Also: SubsystemManager, SubsystemDescriptor.
*Note:* This is deprecated, use afterReloadSubsystems instead.