Two routes to go hear.
Aggression is a learned behaviour and what can be learned can be unlearned. However, as this isn’t the first occurrence it’s probably safe to assume that the owner isn’t willing to do the work to help the dog. Most people aren’t. Just remember, that dog isn’t giving you a hard time, that dog is having a hard time.
I say this while looking at a very settled foster dog who was recently so stressed he ate through breeze block to try and escape.
Ideally, both the dog and the owner get help. It’s hard work, will take time and money.
The other option is you report it, the owner might get prosecuted and the dog will get destroyed.
If they haven’t already, someone will be along to tell you it will be a child’s face next and it’s your civic duty to have the dog destroyed.
How are you feeling about it?