Grant BouncyCastle getProperty permission for datasource encryption

[dai-chen]

Description

This PR fixed the 2.19.6 release IT failure (#5579) due to the BouncyCastle version bump in opensearch-project/OpenSearch#22296.

Ref to opensearch-project/OpenSearch#17393 and opensearch-project/security#4266, #4270 for the same getProperty.org.bouncycastle.* grant.

Related Issues

Resolves #5579

Check List

• New functionality includes testing.
• New functionality has been documented.
• New functionality has javadoc added.
• New functionality has a user manual doc added.
• New PPL command checklist all confirmed.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff or -s.
• Public documentation issue/PR created.

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[github-actions]

PR Code Analyzer ❗

AI-powered 'Code-Diff-Analyzer' found issues on commit 563804f.

Path	Line	Severity	Description
plugin/src/main/plugin-metadata/plugin-security.policy	33	low	Wildcard SecurityPermission 'getProperty.org.bouncycastle.*' grants read access to all BouncyCastle security properties rather than a specific minimal set. While read-only and scoped to the org.bouncycastle namespace, the wildcard is broader than the principle of least privilege would suggest. The stated justification (datasource credential encryption) is plausible and BouncyCastle is a well-known cryptography library, so this does not indicate malicious intent — but maintainers should confirm no narrower property name can be used instead.

The table above displays the top 10 most important findings.

Total: 1 | Critical: 0 | High: 0 | Medium: 0 | Low: 1

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[github-actions]

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🧪 No relevant tests

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