Policy violation audit supress action sometimes not tracked

### Current Behavior

When auditing a policy violation I observed, that supress actions are not always tracked.

### Steps to Reproduce

Have a new empty violation:

Click "supress" **before** selecting anything in the dropdown:

(trail stays emtpy)

Click supress again. Now an "unsupressed" action is tracked in the audit trail

Note: the order matters: If you FIRST select anything in the dropdown and THEN click supress, it's tracked.

### Expected Behavior

Supress is always tracked in the audit trail

### Dependency-Track Version

4.14.0

### Dependency-Track Distribution

Container Image

### Database Server

PostgreSQL

### Database Server Version

10

### Browser

Google Chrome

### Checklist

- [x] I have read and understand the [contributing guidelines](https://github.com/DependencyTrack/dependency-track/blob/master/CONTRIBUTING.md#filing-issues)
- [x] I have checked the [existing issues](https://github.com/DependencyTrack/dependency-track/issues) for whether this defect was already reported