Fix - Add missing watch when creating VirtualMachineSnapshot controller

[kolluria]

What this PR does / why we need it:

As part of #3633, I introduced a change to VirtualMachineSnapshot reconciler which is incomplete as the Application Builder doesn't know which resource of watch over. This has resulted in the following error -

Failed to build application controller. Err: there are no watches configured, controller will never get triggered. Use For(), Owns(), Watches() or WatchesRawSource() to set them up

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #3633

Testing done:
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If jtest is used to trigger precheckin tests, paste the result after jtest completes and remove [WIP] in the PR subject.
The review cycle will start, only after "[WIP]" is removed from the PR subject.

Special notes for your reviewer:

Release note:

[kolluria]

/cc @deepakkinni
/assign @kolluria
/ok-to-test

[deepakkinni]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: deepakkinni, kolluria

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[kolluria]

ok-to-test-wcp
ok-to-test-tkg