[Codec] Update codec checkpoint config
# What does this PR do ?

Update codec configs to always save NeMo checkpoint with best `val_loss`.

**Collection**: TTS

# Changelog 
- Updated `checkpoint_callback_params` to always save `NeMo` checkpoint with best `val_loss` and to save 5 best checkpoints
- Set `create_wandb_logger` to `true`, since `model.log_config.log_wandb` is set to `true` by default

# Usage
N/A

# Before your PR is "Ready for review"
**Pre checks**:
- [x] Make sure you read and followed [Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md)
- [ ] Did you write any new necessary tests?
- [ ] Did you add or update any necessary documentation?
- [ ] Does the PR affect components that are optional to install? (Ex: Numba, Pynini, Apex etc)
  - [ ] Reviewer: Does the PR have correct import guards for all optional libraries?
  
**PR Type**:
- [ ] New Feature
- [x] Bugfix
- [ ] Documentation

If you haven't finished some of the above items you can still open "Draft" PR.


## Who can review?

Anyone in the community is free to review the PR once the checks have passed. 
[Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md) contains specific people who can review PRs to various areas.

# Additional Information
* Related to # (issue)
