[automation] update elastic stack version for testing 8.2.0-a12f7069

[apmmachine]

What

Bump stack version with the latest one.

Further details

[start_time:Fri, 4 Mar 2022 14:54:03 GMT, release_branch:master, prefix:, end_time:Fri, 4 Mar 2022 20:48:39 GMT, manifest_version:2.0.0, version:8.2.0-SNAPSHOT, branch:master, build_id:8.2.0-a12f7069, build_duration_seconds:21276]

[elasticmachine]

💚 Build Succeeded

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Build stats

• Start Time: 2022-03-07T15:02:51.827+0000

• Duration: 99 min 18 sec

Test stats 🧪

Test	Results
Failed	0
Passed	42999
Skipped	3846
Total	46845

💚 Flaky test report

Tests succeeded.

🤖 GitHub comments

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

• /test : Re-trigger the build.

• /package : Generate the packages and run the E2E tests.

• /beats-tester : Run the installation tests with beats-tester.

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

[v1v]

/test

[mergify]

Automatically approving mergify