Remove storageFactory field from subclasses of InputStreamFile

The InputStreamFile class has a field called storageFactory which holds the BaseStorageFactory instance that created it. This field is accessible by all subclasses of InputStream. Still, each subclass has its own storageFactory field which shadows the field in the parent class and holds a reference to the exact same factory instance as the parent.

I'd like to remove the extra fields in the subclasses in order to simply the code and silence IDE warnings about the shadowing.