Add autoclass to GCS

[jeroenmonteban]

Add the option to create a GCS bucket with autoclass enabled. Autoclass automatically transitions objects in a bucket to appropriate storage class based on each object's access pattern.

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Checklist

I applicable, I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass

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[ludoo]

Thanks for this, dropped a note but I will resolve it once/if tests pass.