PLT-5745 Cleaning up duplicate calls (#7298)

* PLT-5745 Cleaning up duplicate calls

* Fixing missing calls

* Fixing broken test

app/plugins.go

@@ -50,8 +50,8 @@ func (api *PluginAPI) GetDirectChannel(userId1, userId2 string) (*model.Channel,
 	return GetDirectChannel(userId1, userId2)
 }
 
-func (api *PluginAPI) CreatePost(post *model.Post, teamId string) (*model.Post, *model.AppError) {
-	return CreatePost(post, teamId, true)
+func (api *PluginAPI) CreatePost(post *model.Post) (*model.Post, *model.AppError) {
+	return CreatePostMissingChannel(post, true)
 }
 
 func (api *PluginAPI) I18n(id string, r *http.Request) string {