Platform agnostic device removal

[torredil]

Signed-off-by: Eddie Torres [email protected]

Is this a bug fix or adding new feature?

• The current device removal process in the driver is not working correctly for Windows customers as provisioned volumes can get stuck in the detachment process.
• In the current implementation, volumes are unstaged and unpublished by calling the Unmount function from the "k8s.io/mount-utils" package. On Windows, this function executes cmd rmdir ${target} which does not guarantee a successful volume unstage and graceful device removal.

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

• The device removal process is improved on Windows by using the CSI Proxy API to flush the data cache and remove the global staging path.
• The disk is offlined to ensure graceful device removal as per EC2 documentation.
• Some general refactoring is done to improve code quality and ensure implementation is platform agnostic.

What testing is done?

make test succeeds.

1. Build and upload container images to a registry.
2. Change the image in the helm chart.
3. Test unmounting functionality using the new helm chart.

[gtxu]

/ok-to-test

[k8s-triage-robot]

Unknown CLA label state. Rechecking for CLA labels.

Send feedback to sig-contributor-experience at kubernetes/community.

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[gtxu]

/lgtm

[gtxu]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: gtxu, torredil

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