[automation] update elastic stack version for testing 8.4.0-a6aa9f3b#631

Merged

mergify[bot] merged 1 commit intomainfrom update-stack-version-20220628051537-main

Jun 28, 2022

+2-2

Commits on Jun 28, 2022

[Automation] Update elastic stack version to 8.4.0-a6aa9f3b for testing
apmmachine
committed