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/notify_admin.go

@@ -154,7 +154,7 @@ func (a *App) pluginInstallAdminNotifyPost(c request.CTX, userBasedData map[stri
 	props["requested_plugins_by_user_ids"] = userBasedData
 	post.SetProps(props)
 
-	_, appErr = a.CreatePost(c, post, channel, false, true)
+	_, appErr = a.CreatePost(c, post, channel, model.CreatePostFlags{SetOnline: true})
 	if appErr != nil {
 		c.Logger().Warn("Error creating post", mlog.Err(appErr))
 	}
@@ -193,7 +193,7 @@ func (a *App) upgradePlanAdminNotifyPost(c request.CTX, workspaceName string, us
 	props["trial"] = trial
 	post.SetProps(props)
 
-	_, appErr = a.CreatePost(c, post, channel, false, true)
+	_, appErr = a.CreatePost(c, post, channel, model.CreatePostFlags{SetOnline: true})
 
 	if appErr != nil {
 		c.Logger().Warn("Error creating post", mlog.Err(appErr))