Feed Ok into VirtioPciDeviceActivator and assert that activate returns
Ok, device_activated becomes true, DEVICE_NEEDS_RESET is not set,
status is otherwise unchanged, no Config interrupt is delivered, and
the barrier waiter unblocks normally.
Assisted-by: Claude:Opus-4.7
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>