title: Get source repo commit hash in AWS code build step
body: <p>Is there a way to get the commit hash from inside an AWS CodeBuild build step? I tried using the CODEBUILD_RESOLVED_SOURCE_VERSION but it returns the IaC repo's Commit Id instead of the source repo's.</p>
  
  <p>I know there is a way to get it if you have the execution id:</p>
  
  <pre><code>aws codepipeline get-pipeline-execution --pipeline-name my-pipeline --pipeline-execution-id e550c757-434a-4c94-8e2e-5122ca14d861
  </code></pre>
  
  <p>However I don't have the pipeline-execution-id either. I only have the CODEBUILD_BUILD_ID.</p>