Unpleasent behavior when enrolling to non existing policy

[michalpristas]

When agent we try to add fleet-server agent specifying -fleet-server-policy with an incorrect value (e.g typo) agent misbehaves.

It spins up fleet server, fleet server tries to read policy index with a specified policy which is empty, and retries and retries

behavior is not well defined in fleet server as well

m.reporter.UpdateState(client.UnitStateStarting, fmt.Sprintf("Waiting on policy with Fleet Server integration: %s", m.policyID), nil) //nolint:errcheck // not clear what to do in failure cases

Once fleet server issue is addressed we should see what can we do not to hang endlessly and verify we're not leaking memory

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)