Fix capacity value after resize to lower capacity

[adamginna-dell]

Description

ControllerExpandVolume function in idempotency path change capacity to 0 and it cause error. This change fix capacity value after resize to lower capacity.

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, vetting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have commented my code, particularly in hard-to-understand areas
• Backward compatibility is not broken

Test:

• Unit test

[mdutka-dell]

LGTM