Move VSphere diskSizeGB from extended to basic/required options

[floreks]

What this PR does / why we need it:
Moved VSPhere's diskSizeGB from optional to required options.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #3118

Release note:

Changed VSPhere's diskSizeGB option from optional to required.

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: floreks

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• OWNERS [floreks]

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[floreks]

I guess we should also cherry-pick it.

/cherrypick release/v2.16

[kubermatic-bot]

@floreks: once the present PR merges, I will cherry-pick it on top of release/v2.16 in a new PR and assign it to you.

In response to this:

I guess we should also cherry-pick it.

/cherrypick release/v2.16

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[maciaszczykm]

/lgtm

[kubermatic-bot]

LGTM label has been added.

Git tree hash: 7a235f105d376f54662e80d4c6e0601298b4f33b

[codecov]

Codecov Report

Merging #3121 (e91b827) into master (795a3b5) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##           master    #3121   +/-   ##
=======================================
  Coverage   51.71%   51.71%           
=======================================
  Files         243      243           
  Lines        8505     8505           
  Branches      882      882           
=======================================
  Hits         4398     4398           
  Misses       4103     4103           
  Partials        4        4           

Impacted Files	Coverage Δ
src/app/node-data/dialog/component.ts	23.52% <0.00%> (ø)
src/app/shared/entity/node.ts	46.98% <ø> (ø)

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[floreks]

/test pre-dashboard-test-e2e-ce

[floreks]

/retest

[kubermatic-bot]

@floreks: new pull request created: #3123

In response to this:

I guess we should also cherry-pick it.

/cherrypick release/v2.16

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.