Use elastic-agent-complete Docker image

[mtojek]

Issue: #510

[elasticmachine]

💚 Build Succeeded

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Build stats

• Start Time: 2021-09-22T10:48:52.925+0000

• Duration: 24 min 27 sec

• Commit: d75df84

Test stats 🧪

Test	Results
Failed	0
Passed	433
Skipped	5
Total	438

[mtojek]

I did some manual testing and it went well.