Set agent.id to Fleet Agent ID for each metric/log monitoring input (#…

…26776) (#26849)

An earlier commit #26548 set the same value using a single global processor,
but that doesn't seem to make it into the final config so it had no effect. So this
sets the agent.id at the same places where elastic_agent.id is added.

(cherry picked from commit aa62bba)

Co-authored-by: Andrew Kroh <andrew.kroh@elastic.co>

x-pack/elastic-agent/pkg/agent/operation/monitoring.go

@@ -264,6 +264,14 @@ func (o *Operator) getMonitoringFilebeatConfig(outputType string, output interfa
 						},
 					},
 				},
+				{
+					"add_fields": map[string]interface{}{
+						"target": "agent",
+						"fields": map[string]interface{}{
+							"id": o.agentInfo.AgentID(),
+						},
+					},
+				},
 				{
 					"drop_fields": map[string]interface{}{
 						"fields": []string{
@@ -319,6 +327,14 @@ func (o *Operator) getMonitoringFilebeatConfig(outputType string, output interfa
 							},
 						},
 					},
+					{
+						"add_fields": map[string]interface{}{
+							"target": "agent",
+							"fields": map[string]interface{}{
+								"id": o.agentInfo.AgentID(),
+							},
+						},
+					},
 					{
 						"drop_fields": map[string]interface{}{
 							"fields": []string{
@@ -339,16 +355,6 @@ func (o *Operator) getMonitoringFilebeatConfig(outputType string, output interfa
 		"output": map[string]interface{}{
 			outputType: output,
 		},
-		"processors": []map[string]interface{}{
-			{
-				"add_fields": map[string]interface{}{
-					"target": "agent",
-					"fields": map[string]interface{}{
-						"id": o.agentInfo.AgentID(),
-					},
-				},
-			},
-		},
 	}
 
 	return result, true
@@ -398,6 +404,14 @@ func (o *Operator) getMonitoringMetricbeatConfig(outputType string, output inter
 						},
 					},
 				},
+				{
+					"add_fields": map[string]interface{}{
+						"target": "agent",
+						"fields": map[string]interface{}{
+							"id": o.agentInfo.AgentID(),
+						},
+					},
+				},
 			},
 		}, map[string]interface{}{
 			"module":     "http",
@@ -437,6 +451,14 @@ func (o *Operator) getMonitoringMetricbeatConfig(outputType string, output inter
 						},
 					},
 				},
+				{
+					"add_fields": map[string]interface{}{
+						"target": "agent",
+						"fields": map[string]interface{}{
+							"id": o.agentInfo.AgentID(),
+						},
+					},
+				},
 				{
 					"copy_fields": map[string]interface{}{
 						"fields": []map[string]interface{}{
@@ -520,6 +542,14 @@ func (o *Operator) getMonitoringMetricbeatConfig(outputType string, output inter
 					},
 				},
 			},
+			{
+				"add_fields": map[string]interface{}{
+					"target": "agent",
+					"fields": map[string]interface{}{
+						"id": o.agentInfo.AgentID(),
+					},
+				},
+			},
 			{
 				"copy_fields": map[string]interface{}{
 					"fields": []map[string]interface{}{
@@ -571,16 +601,6 @@ func (o *Operator) getMonitoringMetricbeatConfig(outputType string, output inter
 		"output": map[string]interface{}{
 			outputType: output,
 		},
-		"processors": []map[string]interface{}{
-			{
-				"add_fields": map[string]interface{}{
-					"target": "agent",
-					"fields": map[string]interface{}{
-						"id": o.agentInfo.AgentID(),
-					},
-				},
-			},
-		},
 	}
 
 	return result, true