[Content Improvement] R BYO notebook has reverted to Python?

**Link to the notebook**

[r_examples/r_sagemaker_hello_world/r_sagemaker_hello_world.ipynb](https://github.com/aws/amazon-sagemaker-examples/blob/8b07283364001da411d98d2ad5c2838a700b7bdc/r_examples/r_sagemaker_hello_world/r_sagemaker_hello_world.ipynb)

(maybe also [r_examples/r_in_sagemaker_processing/r_in_sagemaker_processing.ipynb](https://github.com/aws/amazon-sagemaker-examples/blob/8b07283364001da411d98d2ad5c2838a700b7bdc/r_examples/r_in_sagemaker_processing/r_in_sagemaker_processing.ipynb))

**What aspects of the notebook can be improved?**

In PR #1221 I ported the old `advanced_functionality/r_bring_your_own` sample's notebook ([here](https://github.com/aws/amazon-sagemaker-examples/tree/67226906f83751ae188fd1c9a32fd9962c36fc4e/advanced_functionality/r_bring_your_own)) from Python to R, because (tautologically) *data scientists who are using R, probably use R?*

It seems like that sample was since deleted - I guess as part of clean-up to keep the R materials together.

As far as I can tell, we're now in a situation where all the R samples are either:

- R notebooks but using built-in algorithms, or
- R scripts but using Python notebooks to spin up the jobs (the training BYO/HPO, and the Processing samples above)

**What are your suggestions?**

Please migrate the notebooks for R BYO samples to R (still using SageMaker SDK via Reticulate), because (IMO?) it's less likely that an R-using team would want to orchestrate their experiments with Python.

Happy to try and support implementation for this, but wanted to check whether there was some deliberate reason for returning to R / removing the previous one first! Thanks

Start by reviewing r_examples/r_sagemaker_hello_world/r_sagemaker_hello_world.ipynb and, if in scope, r_examples/r_in_sagemaker_processing/r_in_sagemaker_processing.ipynb, then compare their history with PR #1221 and the deleted advanced_functionality/r_bring_your_own sample. Done means the agreed R BYO examples use R notebooks while retaining the requested SageMaker workflow.

Written by the indexing model from the issue text.