cob_simulation: 0.5.2-0 in 'hydro/distribution.yaml' [bloom]

Increasing version of package(s) in repository `cob_simulation` to `0.5.2-0`:

- distro file: `hydro/distribution.yaml`
- bloom version: `0.5.2`
- previous version for package: `0.5.1-6`

## cob_bringup_sim

- No changes

## cob_gazebo

```
* no OpenCV required in cob_gazebo
* Contributors: ipa-fxm
```

## cob_gazebo_objects

- No changes

## cob_gazebo_worlds

- No changes

## cob_simulation

- No changes