PIM-2133 Made the Metric conversion listener object mapper agnostic

| Q                   | A
| ------------------- | ---
| Bug fix?            | no
| New feature?        | no 
| BC breaks?          | no
| Tests pass?         | yes
| Scenarios pass?     | 742
| Checkstyle issues?  | ?
| Changelog updated?  | no
| Fixed tickets       | PIM-2133
| Doc PR              |