Filter duplicate canonical value display labels

[sadilchamishka]

Purpose

The duplicated canonical values send to the processing will be filtered.

Related Issues

• Attribute's value options can be duplicated with same display value product-is#25335

[wso2-engineering-bot]

AI Agent Log Improvement Checklist

⚠️ Warning: AI-Generated Review Comments

• The log-related comments and suggestions in this review were generated by an AI tool to assist with identifying potential improvements. Purpose of reviewing the code for log improvements is to improve the troubleshooting capabilities of our products.
• Please make sure to manually review and validate all suggestions before applying any changes. Not every code suggestion would make sense or add value to our purpose. Therefore, you have the freedom to decide which of the suggestions are helpful.

✅ Before merging this pull request:

• Review all AI-generated comments for accuracy and relevance.
• Complete and verify the table below. We need your feedback to measure the accuracy of these suggestions and the value they add. If you are rejecting a certain code suggestion, please mention the reason briefly in the suggestion for us to capture it.

Comment	Accepted (Y/N)	Reason
#### Log Improvement Suggestion No: 1	Y

[Copilot]

Pull Request Overview

This PR filters out duplicate canonical value display labels when creating local claims. The change ensures that if multiple canonical values have the same label, only the first occurrence is preserved.

• Replaces direct array-to-JSON conversion with a deduplication process using HashSet and Stream operations
• Uses Collectors.toMap() with a merge function to handle duplicate labels by keeping the first value

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[jenkins-is-staging]

PR builder started
Link: https://github.com/wso2/product-is/actions/runs/17131511388

[jenkins-is-staging]

PR builder completed
Link: https://github.com/wso2/product-is/actions/runs/17131511388
Status: failure

[jenkins-is-staging]

PR builder completed
Link: https://github.com/wso2/product-is/actions/runs/17131511388
Status: success

[jenkins-is-staging]

Approving the pull request based on the successful pr build https://github.com/wso2/product-is/actions/runs/17131511388

[sadilchamishka]

Integration tests run in fork

• https://github.com/sadilchamishka/product-is/actions/runs/17145739596