"bash: cannot set terminal process group (-1): Inappropriate ioctl for device" printed at the start of sagemaker jobs

The entrypoint script for the containers is executed with monitor mode enabled (using -m flag), eg. here https://github.com/aws/sagemaker-pytorch-container/blob/97e611b4cb2df13d966d508e56d1c990439b2163/docker/1.3.1/py3/Dockerfile.gpu#L166

This prints the following message at the start of any sagemaker job that uses the container:
```
bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell
```

Removing the -m flag gets rid of this message. Is there a particular reason for using this flag? If not we should remove it from all Dockerfiles.

Start with the Dockerfile entrypoint invocation shown in the issue and inspect the other Dockerfiles for the same monitor-mode flag. Confirm why the flag is used, remove it if no longer needed, and verify that SageMaker jobs no longer print the terminal process-group and job-control messages.

Written by the indexing model from the issue text.