Fix refresh request consumer invocation for web identity credentials

[YuqiGuo105]

Motivation and Context

The Consumer overload of StsAssumeRoleWithWebIdentityCredentialsProvider.Builder.refreshRequest eagerly built an AssumeRoleWithWebIdentityRequest and delegated to the fixed-request overload. As a result, later credential refreshes reused the same request and web identity token instead of invoking the consumer again.

This can cause credential refresh to fail after a dynamically supplied web identity token expires.

Fixes #5709

Modifications

• Defer request construction by wrapping the builder mutation in the existing request Supplier.
• Invoke the Consumer whenever credentials are refreshed and a new request is obtained.
• Clarify the per-refresh invocation behavior in the method Javadoc.
• Add a regression test that forces two credential refreshes and verifies that STS receives token-1 followed by token-2.

The change is intentionally scoped to the Consumer overload on StsAssumeRoleWithWebIdentityCredentialsProvider. The fixed request and explicit Supplier overloads are unchanged.

Testing

• ./mvnw install -pl :sts -P quick -am
• ./mvnw -pl :sts -Dtest=StsAssumeRoleWithWebIdentityCredentialsProviderTest -Dspotbugs.skip=true test
• Verified that the new regression test fails before the implementation change with token-1 used twice.
• Verified that all 7 tests in StsAssumeRoleWithWebIdentityCredentialsProviderTest pass after the change.
• Checkstyle completed with 0 violations.
• git diff --check completed successfully.

Screenshots

Not applicable.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• I have read the CONTRIBUTING document
• Local run of mvn install succeeds
• My code follows the code style of this project
• My change requires a change to the Javadoc documentation
• I have updated the Javadoc documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed
• I have added a changelog entry
• My change is to implement 1.11 parity feature and I have updated LaunchChangelog

License

• I confirm that this pull request can be released under the Apache 2 license

This pull request was generated with assistance from AI tools and reviewed by Yuqi Guo.