[automation] update elastic stack version for testing 8.5.0-a415b54b

[ghost]

What

Bump stack version with the latest one.

Further details

[start_time:Tue, 27 Sep 2022 00:18:44 GMT, release_branch:8.5, prefix:, end_time:Tue, 27 Sep 2022 06:11:34 GMT, manifest_version:2.1.0, version:8.5.0-SNAPSHOT, branch:8.5, build_id:8.5.0-a415b54b, build_duration_seconds:21170]

[elasticmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Start Time: 2022-09-28T05:17:39.370+0000

• Duration: 17 min 12 sec

Test stats 🧪

Test	Results
Failed	0
Passed	4955
Skipped	17
Total	4972

💚 Flaky test report

Tests succeeded.

🤖 GitHub comments

Expand to view the GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

• /package : Generate the packages.

• run integration tests : Run the Elastic Agent Integration tests.

• run end-to-end tests : Generate the packages and run the E2E Tests.

• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	97.333% (73/75)	👍
Files	67.797% (160/236)	👍
Classes	68.182% (315/462)	👍
Methods	52.417% (889/1696)	👍
Lines	38.683% (9578/24760)	👎 -0.032
Conditionals	100.0% (0/0)	💚

[mergify]

Automatically approving mergify