MD5 Hash of offline_store_spark_runner.py

[epps]

Description

This PR ensures that newer/different versions of offline_store_spark_runner.py are uploaded to cloud object storage by writing the MD5 hash of the file in the container and adding this as a suffix to the filename that's uploaded.

Type of change

Select type(s) of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have fixed any merge conflicts

[ahmadnazeri]

LGTM; only thing is if we want to have the ability to overriding it to previous versions.