Adds support for GMs in shared channels (#31403)

* Adds support for GMs in shared channels

* Fix linter

* Remove creatorID from slack call

---------

Co-authored-by: Miguel de la Cruz <miguel@ctrlz.es>

server/channels/store/timerlayer/timerlayer.go

@@ -2394,10 +2394,10 @@ func (s *TimerLayerChannelStore) Restore(channelID string, timestamp int64) erro
 	return err
 }
 
-func (s *TimerLayerChannelStore) Save(rctx request.CTX, channel *model.Channel, maxChannelsPerTeam int64) (*model.Channel, error) {
+func (s *TimerLayerChannelStore) Save(rctx request.CTX, channel *model.Channel, maxChannelsPerTeam int64, channelOptions ...model.ChannelOption) (*model.Channel, error) {
 	start := time.Now()
 
-	result, err := s.ChannelStore.Save(rctx, channel, maxChannelsPerTeam)
+	result, err := s.ChannelStore.Save(rctx, channel, maxChannelsPerTeam, channelOptions...)
 
 	elapsed := float64(time.Since(start)) / float64(time.Second)
 	if s.Root.Metrics != nil {