Make a note about the firewall in HA mode (#1563)
Make a note about the firewall in HA mode (#1563)

* Make a note about the firewall in HA mode

prometheus/alertmanager,prometheus/alertmanager,GoogleCloudPlatform/alertmanager,prometheus/alertmanager,GoogleCloudPlatform/alertmanager,GoogleCloudPlatform/alertmanager,prometheus/alertmanager,GoogleCloudPlatform/alertmanager