fix(compute-mig): add correct type optionality for metrics in autosca…

[NotArpit]

Description

In the //modules/compute-mig module there is a mismatch between the optionality of types and what the upstream terraform docs mention for autoscaler_config.metrics.(type|target_value). It seems only the autoscaler_config.metrics.name type is required.

Notes

I've ran tools/tfdoc.py but linting seems to be failing, can maintainers PTAL?

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

[ludoo]

Pass the --files otpion to tfdoc. We should force it in the tfdoc tag itself, sorry for that.

[ludoo]

Well no it's the opposite: don't enable files in tfdoc :)

[NotArpit]

@ludoo all done :)

[ludoo]

Thanks a lot for this PR!