fix: ensure correct run context for 'elasticsearch' (legacy) instrumentation

[trentm]

Refs: #2430

Checklist

• Implement code
• Add tests
• Add CHANGELOG.asciidoc entry

[apmmachine]

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Build stats

• Reason: null

• Start Time: 2022-01-28T18:56:57.132+0000

• Duration: 25 min 6 sec

• Commit: 38f39c1

Test stats 🧪

Test	Results
Failed	0
Passed	243775
Skipped	0
Total	243775

🤖 GitHub comments

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

• /test : Re-trigger the build.

• run module tests for <modules> : Run TAV tests for one or more modules, where <modules> can be either a comma separated list of modules (e.g. memcached,redis) or the string literal ALL to test all modules

• run benchmark tests : Run the benchmark test only.

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

[trentm]

run module tests for elasticsearch