This commit adds a bool named PeerRelay to Hostinfo, to identify the host's status of acting as a peer relay.
Considering the RelayServerPort number can be 0, I just made this a bool in stead of a port number. If the port
info is needed in future this would also help indicating if the port was set to 0 (meaning any port in peer relay
context).
Updates tailscale/corp#35862
Signed-off-by: KevinLiang10 <37811973+KevinLiang10@users.noreply.github.com>
5eaaf9786b