MM-49048: do not omit needed wsbroadcast vars (#22156)

* MM-49048: do not omit needed wsbroadcast vars

It seems that we are omitting ContainsSanitizedData, and
ContainsSensitiveData variables in WebsocketBroadcast.
This created a bug in cluster mode, in which we were sending duplicate
events to users whereas normally they would have access to only one of those.

Co-authored-by: Mattermost Build <build@mattermost.com>

app/platform/web_hub_test.go

@@ -4,6 +4,7 @@
 package platform
 
 import (
+	"encoding/json"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -551,3 +552,31 @@ func BenchmarkGetHubForUserId(b *testing.B) {
 		hubSink = th.Service.GetHubForUserId(th.BasicUser.Id)
 	}
 }
+
+func TestClusterBroadcast(t *testing.T) {
+	testCluster := &testlib.FakeClusterInterface{}
+
+	th := SetupWithCluster(t, testCluster)
+	defer th.TearDown()
+
+	ev := model.NewWebSocketEvent("test_event", "", "", "", nil, "")
+	broadcast := &model.WebsocketBroadcast{
+		ContainsSanitizedData: true,
+		ContainsSensitiveData: true,
+	}
+	ev = ev.SetBroadcast(broadcast)
+	th.Service.Publish(ev)
+
+	messages := testCluster.GetMessages()
+
+	var clusterEvent struct {
+		Event     string                    `json:"event"`
+		Data      map[string]any            `json:"data"`
+		Broadcast *model.WebsocketBroadcast `json:"broadcast"`
+		Sequence  int64                     `json:"seq"`
+	}
+
+	err := json.Unmarshal(messages[0].Data, &clusterEvent)
+	require.NoError(t, err)
+	require.Equal(t, clusterEvent.Broadcast, broadcast)
+}