Add option to automatically upgrade too small volumes to the minimum size

[phuhung273]

What type of PR is this?

/kind feature

Close #2162

What is this PR about? / Why do we need it?

• Add option to automatically upgrade too small volumes to the minimum size

How was this change tested?

Unit test

Does this PR introduce a user-facing change?

Add option to automatically upgrade too small volumes to the minimum size

[k8s-ci-robot]

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[k8s-ci-robot]

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[torredil]

/ok-to-test

[AndrewSirenko]

@phuhung273, thank you for your contribution. This PR may take our team some time to review because many folks are on vacation, and its inclusion may affect the decision of a few other open issues.

We have been moving towards relying on EC2 API as source of truth for input validation, instead hard-coding EC2 limits & massaging user inputs. (See #1879)

This PR introduces more coupling between the driver and today's EBS limits. If EBS expands the min/max volume size ranges next quarter, this version of the driver will become outdated. (For example, EBS has previously increased io2 max IOPS limit)

On the other hand, this parameter is opt-in, which means cluster admins can decide whether they value convenience instead of over-provisioning storage.

Ideally, EC2 would offer an API we could call instead of hard-coding all these limits, so that our driver would not become out of date. But because this API does not exist today, we have to be careful about adding this feature.

[phuhung273]

Thanks for your explanation @AndrewSirenko. Totally respect team's ownership on the product, if team decision is no, i dont mind closing PR.