Snapshot deletion validation during KataConfig removal

[gsid100]

During KataConfig (with peer pods enabled) deletion, we delete the AMI and the snapshot associated with the podvm image. In this PR I Included a validation for ensuring the Snapshot associated with the AMI was deleted properly

- Description of the problem which is fixed/What is the use case
Lack of validation to ensure the snapshot was deleted

- What I did
Added validations to the 'aws-podvm-image-handler.sh' script

- How to verify it

• Create KataConfig
• Save the Snapshot ID associated with the AMI (by running aws cli commands)
• Delete KataConfig
• Examine the logs of the podvm delete pod and verify it shows "Snapshot '${SNAPSHOT_ID}' successfully deleted"

- Description for the changelog
Validating aws ami snapshot is deleted properly during KataConfig removal

[openshift-ci]

Hi @gsid100. Thanks for your PR.

I'm waiting for a openshift member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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