[GCP] Log ListTimeSeries and AggregatedList requests duration

CHANGELOG.next.asciidoc

@@ -320,6 +320,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Add SSL support for aerospike module {pull}38126[38126]
 - Add new metricset network for the vSphere module. {pull}40559[40559]
 - Add new metricset resourcepool for the vSphere module. {pull}40456[40456]
+- Log the total time taken for GCP `ListTimeSeries` and `AggregatedList` requests {pull}40661[40661]
 
 *Metricbeat*
 

x-pack/metricbeat/module/gcp/metrics/compute/metadata.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"strconv"
 	"strings"
+	"time"
 
 	compute "cloud.google.com/go/compute/apiv1"
 	"cloud.google.com/go/compute/apiv1/computepb"
@@ -188,6 +189,11 @@ func (s *metadataCollector) getComputeInstances(ctx context.Context) {
 
 	defer instancesClient.Close()
 
+	start := time.Now()
+	defer func() {
+		s.logger.Debugf("Total time taken for compute AggregatedList request: %s", time.Since(start))
+	}()
+
 	it := instancesClient.AggregatedList(ctx, &computepb.AggregatedListInstancesRequest{
 		Project: s.projectID,
 	})

x-pack/metricbeat/module/gcp/metrics/metrics_requester.go

@@ -124,6 +124,11 @@ func (r *metricsRequester) Metrics(ctx context.Context, serviceName string, alig
 		}
 	}
 
+	start := time.Now()
+	defer func() {
+		r.logger.Debugf("Total time taken for all ListTimeSeries requests: %s and config period: %s", time.Since(start), r.config.period.AsDuration())
+	}()
+
 	for mt, meta := range metricsToCollect {
 		wg.Add(1)