Helm: Update job ttl to make it configurable

[emuthiah]

What this PR does / why we need it:
This PR adds the ability to set non-zero value for .spec.ttlSecondsAfterFinished field of webhook Jobs. It is needed because some CD tools (eg. ArgoCD) are not able to get the status of the completed Job before it is cleaned up and hangs at syncing status. By setting ttlSecondsAfterFinished value to non-zero (eg. 10 seconds), it gives ArgoCD enough time to get the status of the job and complete sync operation.
This change does not break or change existing functionality. It add the ability to change ttlSecondsAfterFinished if required.
Special notes for your reviewer:

If applicable:

• this PR has an associated PR with documentation in akri-docs
• this PR contains unit tests
• added code adheres to standard Rust formatting (cargo fmt)
• code builds properly (cargo build)
• code is free of common mistakes (cargo clippy)
• all Akri tests succeed (cargo test)
• inline documentation builds (cargo doc)
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