Cherry-pick #21047 to 7.x: [Elastic Agent] Fix loggers in composable module.

[blakerouse]

Cherry-pick of PR #21047 to 7.x branch. Original message:

What does this PR do?

Fixes issue where logger.New was being used in the new composable module. This was creating a new logger instead of using application created logger. Providers are updated to take a logger, that is already named correctly.

Why is it important?

So logging works correctly.

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.

Related issues

• Closes Stand-alone agent: it's not possible to get agent documents from elasticsearch #20992

[elasticmachine]

💚 Build Succeeded

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Build stats

• Build Cause: [Pull request #21053 opened]

• Start Time: 2020-09-10T13:28:21.437+0000

• Duration: 37 min 55 sec

Test stats 🧪

Test	Results
Failed	0
Passed	2081
Skipped	6
Total	2087

[ph]

backport lgtm