Add metadata to IAM bindings added.

Such as commit, PR info to be added to IAM bindings condition description.

Look at the IAM binding creation code in the repository, likely in a package handling cloud resource provisioning. Identify where condition descriptions are set and how to inject metadata like commit hash or PR info. Check existing tests for IAM bindings to understand the expected format and add new test cases.

由索引模型根据 Issue 内容生成。