flops callback nemo2 compatible
<!-- pylint-output-strict-mode-false -->

beep boop 🤖: 🙏 The following files have warnings. In case you are familiar with these, please try helping us to improve the code base.

---

Your code was analyzed with PyLint. The following annotations have been identified:

```
************* Module nemo.collections.common.metrics.perf_metrics
nemo/collections/common/metrics/perf_metrics.py:149:4: C0116: Missing function or method docstring (missing-function-docstring)
************* Module nemo.utils.exp_manager
nemo/utils/exp_manager.py:355:0: C0301: Line too long (120/119) (line-too-long)
nemo/utils/exp_manager.py:380:0: C0301: Line too long (124/119) (line-too-long)
nemo/utils/exp_manager.py:384:0: C0301: Line too long (122/119) (line-too-long)
nemo/utils/exp_manager.py:389:0: C0301: Line too long (127/119) (line-too-long)
nemo/utils/exp_manager.py:403:0: C0301: Line too long (120/119) (line-too-long)
nemo/utils/exp_manager.py:410:0: C0301: Line too long (120/119) (line-too-long)
nemo/utils/exp_manager.py:411:0: C0301: Line too long (126/119) (line-too-long)
nemo/utils/exp_manager.py:413:0: C0301: Line too long (136/119) (line-too-long)
nemo/utils/exp_manager.py:415:0: C0301: Line too long (139/119) (line-too-long)
nemo/utils/exp_manager.py:425:0: C0301: Line too long (123/119) (line-too-long)
nemo/utils/exp_manager.py:426:0: C0301: Line too long (128/119) (line-too-long)
nemo/utils/exp_manager.py:427:0: C0301: Line too long (132/119) (line-too-long)
nemo/utils/exp_manager.py:428:0: C0301: Line too long (127/119) (line-too-long)
nemo/utils/exp_manager.py:516:0: C0301: Line too long (122/119) (line-too-long)
nemo/utils/exp_manager.py:604:0: C0301: Line too long (208/119) (line-too-long)
nemo/utils/exp_manager.py:605:0: C0301: Line too long (230/119) (line-too-long)
nemo/utils/exp_manager.py:607:0: C0301: Line too long (178/119) (line-too-long)
nemo/utils/exp_manager.py:644:0: C0301: Line too long (136/119) (line-too-long)
nemo/utils/exp_manager.py:779:0: C0301: Line too long (121/119) (line-too-long)
nemo/utils/exp_manager.py:787:0: C0301: Line too long (156/119) (line-too-long)
nemo/utils/exp_manager.py:834:0: C0301: Line too long (141/119) (line-too-long)
nemo/utils/exp_manager.py:842:0: C0301: Line too long (152/119) (line-too-long)
nemo/utils/exp_manager.py:1112:0: C0301: Line too long (142/119) (line-too-long)
nemo/utils/exp_manager.py:1136:0: C0301: Line too long (154/119) (line-too-long)
nemo/utils/exp_manager.py:1202:0: C0301: Line too long (120/119) (line-too-long)
nemo/utils/exp_manager.py:1221:0: C0301: Line too long (123/119) (line-too-long)
nemo/utils/exp_manager.py:1247:0: C0301: Line too long (121/119) (line-too-long)
nemo/utils/exp_manager.py:91:0: C0115: Missing class docstring (missing-class-docstring)
nemo/utils/exp_manager.py:106:0: C0115: Missing class docstring (missing-class-docstring)
nemo/utils/exp_manager.py:132:0: C0115: Missing class docstring (missing-class-docstring)
nemo/utils/exp_manager.py:141:0: C0115: Missing class docstring (missing-class-docstring)
nemo/utils/exp_manager.py:150:0: C0115: Missing class docstring (missing-class-docstring)
nemo/utils/exp_manager.py:161:0: C0115: Missing class docstring (missing-class-docstring)
nemo/utils/exp_manager.py:276:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:279:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:282:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:285:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:288:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:291:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:294:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:297:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:335:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:338:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:341:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:344:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:1128:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:1229:0: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:1248:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:1251:4: C0116: Missing function or method docstring (missing-function-docstring)
nemo/utils/exp_manager.py:1267:0: C0116: Missing function or method docstring (missing-function-docstring)

-----------------------------------
Your code has been rated at 9.30/10
```

---

Mitigation guide:

* Add sensible and useful docstrings to functions and methods
* For trivial methods like getter/setters, consider adding `# pylint: disable=C0116` inside the function itself
* To disable multiple functions/methods at once, put a `# pylint: disable=C0116` before the first and a `# pylint: enable=C0116` after the last.

By applying these rules, we reduce the occurance of this message in future.

Thank you for improving NeMo's documentation!
# What does this PR do ?

Add a one line overview of what this PR aims to accomplish.

**Collection**: [Note which collection this PR will affect]

# Changelog 
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# Usage
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```python
# Add a code snippet demonstrating how to use this 
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# Before your PR is "Ready for review"
**Pre checks**:
- [ ] Make sure you read and followed [Contributor guidelines](https://github.com/NVIDIA/NeMo/blob/main/CONTRIBUTING.md)
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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)
