Extending BazelTestRunner to Add Custom Metadata to JUnit XML

I've been working on extending the BazelTestRunner to add custom metadata (properties) to the JUnit XML generated by Stripe's Java tests, but I'm hitting a roadblock.

The most promising approach I've found involves using the TestPropertyExporter singleton instance, but I'm uncertain about how it's meant to be used. Additionally, when looking into the Bazel codebase, I noticed that the method testEmittedProperty() in TestSuiteModel.java seems related, but it isn't being called anywhere.

Any advice or alternative suggestions would be appreciated.

Start by tracing BazelTestRunner and the TestPropertyExporter singleton, then inspect TestSuiteModel.java and the unused testEmittedProperty() method. Determine how custom properties should flow into the JUnit XML and identify the relevant Java test coverage. Done means Stripe's Java test output includes the requested metadata and verifies it reliably.

Written by the indexing model from the issue text.