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/report.go

@@ -136,7 +136,7 @@ func (a *App) SendReportToUser(rctx request.CTX, job *model.Job, format string)
 		FileIds: []string{fileInfo.Id},
 	}
 
-	_, err = a.CreatePost(rctx, post, channel, false, true)
+	_, err = a.CreatePost(rctx, post, channel, model.CreatePostFlags{SetOnline: true})
 	return err
 }
 
@@ -250,7 +250,7 @@ func (a *App) StartUsersBatchExport(rctx request.CTX, ro *model.UserReportOption
 			UserId:    systemBot.UserId,
 		}
 
-		if _, err := a.CreatePost(rctx, post, channel, false, true); err != nil {
+		if _, err := a.CreatePost(rctx, post, channel, model.CreatePostFlags{SetOnline: true}); err != nil {
 			rctx.Logger().Error("Failed to post batch export message", mlog.Err(err))
 		}
 	})