[8.19](backport #44716) x-pack/libbeat/management: make UpdateStatus a no-op when no change in state (#44743)

* x-pack/libbeat/management: make UpdateStatus a no-op when no change in state (#44716)

The previous code would update and emit messages always. This would
either spam logs or require that inputs handle state in addition to the
work that is being done by the manager. The change here reflects the
behaviour in libbeat/management which checks for change before updating.

(cherry picked from commit b9ca6d5)

* remove irrelevant changelog entries

---------

Co-authored-by: Dan Kortschak <dan.kortschak@elastic.co>

Author: mergify[bot]

CHANGELOG-developer.next.asciidoc

@@ -230,6 +230,7 @@ client will aggregate metrics by input on this registry. It'll collect
 `events_pipeline_published_total`.{pull}42618[42618] {issue}42761[42761]
 - Add new API to libbeat/monitoring/inputmon. The API allows to register and
 unregister input metrics without relaying on the global 'dataset' namespace.{pull}42618[42618] {issue}42761[42761]
+- Make `x-pack/libbeat/management.BeatV2Manager.UpdateStatus` a no-op if there is no change in state. {pull}44716[44716]
 
 ==== Deprecated
 

x-pack/libbeat/management/managerV2.go

@@ -250,7 +250,9 @@ func (cm *BeatV2Manager) RegisterDiagnosticHook(name string, description string,
 func (cm *BeatV2Manager) UpdateStatus(status status.Status, msg string) {
 	cm.mx.Lock()
 	defer cm.mx.Unlock()
-
+	if cm.status == status && cm.message == msg {
+		return
+	}
 	cm.status = status
 	cm.message = msg
 	cm.updateStatuses()