BUG: IBM Cloud Infra: Return existing VPC ID

[cjschaef]

Fix bug where an existing VPC ID that was found, was not being returned, resulting in attempts to recreate the VPC.

Related: #2140

What this PR does / why we need it:
Resolves 2140

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 #

Special notes for your reviewer:

/area provider/ibmcloud

1. Please confirm that if this PR changes any image versions, then that's the sole change this PR makes.

Release note:

Fix bug when an existing vpc is provided for IBM Cloud Infrastructure but attempts are still made to create it 

[k8s-ci-robot]

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[Prajyot-Parab]

/ok-to-test

[Prajyot-Parab]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cjschaef, Prajyot-Parab

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