Use flags for create post (#28857)

* Use flags for create post

* Remove unintended file

* Fix unintended change and types

---------

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

server/channels/app/team.go

@@ -1286,7 +1286,7 @@ func (a *App) postLeaveTeamMessage(c request.CTX, user *model.User, channel *mod
 		},
 	}
 
-	if _, err := a.CreatePost(c, post, channel, false, true); err != nil {
+	if _, err := a.CreatePost(c, post, channel, model.CreatePostFlags{SetOnline: true}); err != nil {
 		return model.NewAppError("postRemoveFromChannelMessage", "api.channel.post_user_add_remove_message_and_forget.error", nil, "", http.StatusInternalServerError).Wrap(err)
 	}
 
@@ -1304,7 +1304,7 @@ func (a *App) postRemoveFromTeamMessage(c request.CTX, user *model.User, channel
 		},
 	}
 
-	if _, err := a.CreatePost(c, post, channel, false, true); err != nil {
+	if _, err := a.CreatePost(c, post, channel, model.CreatePostFlags{SetOnline: true}); err != nil {
 		return model.NewAppError("postRemoveFromTeamMessage", "api.channel.post_user_add_remove_message_and_forget.error", nil, "", http.StatusInternalServerError).Wrap(err)
 	}