Cherry-pick #26604 to 7.x: Indenting correction for module configuration example

[narph]

Cherry-pick of PR #26604 to 7.x branch. Original message:

What does this PR do?

Fix YAML indenting for module configuration example

Why is it important?

The example given was invalid

Checklist

- [ ] My code follows the style guidelines of this project
- [ ] I have commented my code, particularly in hard-to-understand areas

• I have made corresponding changes to the documentation
  - [ ] I have made corresponding change to the default configuration files
  - [ ] I have added tests that prove my fix is effective or that my feature works
  - [ ] I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Author's Checklist

[elasticmachine]

Pinging @elastic/integrations (Team:Integrations)

[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: 2021-08-24T08:28:00.236+0000

• Duration: 20 min 22 sec

• Commit: e03d1bb

Trends 🧪

❕ Flaky test report

No test was executed to be analysed.

[mergify]

This pull request is now in conflicts. Could you fix it? 🙏
To fixup this pull request, you can check out it locally. See documentation: https://help.github.com/articles/checking-out-pull-requests-locally/

git fetch upstream
git checkout -b backport_26604_7.x upstream/backport_26604_7.x
git merge upstream/7.x
git push upstream backport_26604_7.x