Manual Test Plan 8.4 release

[simitt]

When picking up a test case, please add your name to this overview beforehand and tick the checkbox when finished. Testing can be started when the first build candidate (BC) is available.

Smoke Testing ESS setup

• enable metrics collection in the Cloud UI and check APM Server data show up in the Stack Monitoring UI in Kibana
  (known bug: "Output Events Rate" in stack monitoring is always zero #8383)
• The cloud troubleshooting logs and metrics are accessible as expected.

Thanks to #8303 further smoke tests are run automatically on ESS now.

Test cases from the github board

apm-server 8.4 test-plan
Add yourself as assignee on the PR before you start testing.

Test newly supported Operation Systems

• Add APM Server support for Debian 11 #8729
• Add APM Server Support for Ubuntu 22.04 #8730

Regressions

Link any regressions to this issue.