[Synthetics] Alerting - recovery message does not populate in alert connectors

[dominiqueclarke]

Kibana version: 8.7.0

Description of the problem including expected versus actual behavior: When an alert is recovered, the recovery message does not populate in the alert connector.

I tested both slack and server log connectors. See the below recovery messages from both.

Server log

[2023-02-21T16:02:49.368-05:00][INFO ][plugins.actions.server-log] Server log: The alert for the monitor Always down checking about:blank from North America - US Central is no longer active: .

Slack integration

The alert for the monitor Alerting connectors test 2 checking about:blank from Asia/Pacific - Japan is no longer active: .

There should be a recovery message after no longer active: and before ..

Steps to reproduce:

1. Create a default alert connector in the Synthetics setting page
2. Create an always down monitor to trigger an alert. Confirm the alert was sent to your connector
3. Adjust your monitor to now pass. Observe the recovery message is missing from the alert connector

[elasticmachine]

Pinging @elastic/uptime (Team:uptime)

[dominiqueclarke]

I've confirmed that the recovery message is missing for when the monitor is status UP, but does appear when the monitor is deleted or the location is removed.

[justinkambic]

Post-FF Testing LGTM