[APM] Anomalies not displayed for unconnected services

[dgieselaar]

Looks like anomalies are not displayed for services that do not have any connections. In the following example, anomalies are available for the opbeans-dotnet service, but not displayed in service maps:

They are being displayed in the service inventory:

The ML UI indeed does display anomalies for the opbeans-dotnet service:

[elasticmachine]

Pinging @elastic/apm-ui (Team:apm)

[ogupte]

Closing this as it was fixed in another PR: #80430