SPLAT-2132: introduce SHARED_DIR such that vSphere platform type can build creds

[rvanderp3]

What this PR does / why we need it:
SHARED_DIR is missing and result in platform vSphere failing to start

Which issue(s) this PR fixes:
Fixes SPLAT-2132

Checklist

• Subject and description added to both, commit and PR.
• Relevant issues have been referenced.
• [-] This change includes docs.
• [-] This change includes unit tests.

[openshift-ci]

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