[Components][PropertyAccess] Fix PropertyAccessorBuilder usage

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.3, 2.4, 2.5
| Fixed tickets |

See https://github.com/symfony/PropertyAccess/blob/2.3/PropertyAccess.php

`getPropertyAccessorBuilder` does not exist. But the right fix might be to add the missing method.