This commit updates the logic of vipServicesFromPrefsLocked, so that it would return the vipServices list
even when service host is only advertising the service but not yet serving anything. This makes control
always get accurate state of service host in terms of serving a service.
Fixestailscale/corp#26843
Signed-off-by: KevinLiang10 <37811973+KevinLiang10@users.noreply.github.com>