[filebeat][gcp-pubsub] - Set EventNormalization as false (#36716)

* Update EventNormalization as false for GCP Pubsub

CHANGELOG.next.asciidoc

@@ -220,6 +220,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Improve error logging in HTTPJSON input. {pull}36529[36529]
 - Disable warning message about ingest pipeline loading when running under Elastic Agent. {pull}36659[36659]
 - Add input metrics to http_endpoint input. {issue}36402[36402] {pull}36427[36427]
+- Remove Event Normalization from GCP PubSub Input. {pull}36716[36716]
 - Update mito CEL extension library to v1.6.0. {pull}36651[36651]
 - Added support for new features & removed partial save mechanism in the Azure Blob Storage input. {issue}35126[35126] {pull}36690[36690]
 - Improve template evaluation logging for HTTPJSON input. {pull}36668[36668]

x-pack/filebeat/input/gcppubsub/input.go

@@ -154,6 +154,11 @@ func NewInput(cfg *conf.C, connector channel.Connector, inputContext input.Conte
 				}
 			}),
 		),
+		Processing: beat.ProcessingConfig{
+			// This input only produces events with basic types so normalization
+			// is not required.
+			EventNormalization: boolPtr(false),
+		},
 	})
 	if err != nil {
 		return nil, err
@@ -322,3 +327,6 @@ func (in *pubsubInput) newPubsubClient(ctx context.Context) (*pubsub.Client, err
 
 	return pubsub.NewClient(ctx, in.ProjectID, opts...)
 }
+
+// boolPtr returns a pointer to b.
+func boolPtr(b bool) *bool { return &b }