App Config - Audience policy

[mrm9084]

Description

Adds an Audience Policy to give a better error message on Audience failures in clouds such as Bleu.

All SDK Contribution checklist:

• The pull request does not introduce [breaking changes]
• CHANGELOG is updated for new features, bug fixes or other significant changes.
• I have read the contribution guidelines.

General Guidelines and Best Practices

• Title of the pull request is clear and informative.
• There are a small number of commits, each of which have an informative message. This means that previously merged commits do not appear in the history of the PR. For more information on cleaning up the commits in your PR, see this page.

Testing Guidelines

• Pull request includes test coverage for the included changes.

[Copilot]

Pull Request Overview

This PR adds an AudiencePolicy to the Azure App Configuration SDK for Java to provide more user-friendly error messages when Azure Active Directory audience-related authentication failures occur, particularly in non-public Azure clouds (such as Azure China or Azure Government). The policy intercepts HTTP responses containing the AAD error code "AADSTS500011" and replaces the error message with clearer guidance based on whether an audience was configured or not.

Key Changes

• Added AudiencePolicy class that implements HttpPipelinePolicy to detect and transform audience-related authentication errors
• Integrated the policy into the HTTP pipeline in ConfigurationClientBuilder
• Added comprehensive unit tests covering both sync and async scenarios
• Updated CHANGELOG to document the new feature

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

File	Description
sdk/appconfiguration/azure-data-appconfiguration/src/main/java/com/azure/data/appconfiguration/implementation/AudiencePolicy.java	New policy class that intercepts AAD audience errors and provides clearer error messages based on whether an audience was configured
sdk/appconfiguration/azure-data-appconfiguration/src/main/java/com/azure/data/appconfiguration/ConfigurationClientBuilder.java	Integrates AudiencePolicy into the HTTP pipeline before retry policies
sdk/appconfiguration/azure-data-appconfiguration/src/test/java/com/azure/data/appconfiguration/implementation/AudiencePolicyTest.java	Comprehensive test coverage for the new policy including sync/async scenarios, error transformation, and edge cases
sdk/appconfiguration/azure-data-appconfiguration/CHANGELOG.md	Documents the new audience policy feature for better error messaging