[8.0](backport #29969) [Filebeat] Improve aws-s3 gzip file detection to avoid false negatives

[mergify]

This is an automatic backport of pull request #29969 done by Mergify.

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[elasticmachine]

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• Start Time: 2022-01-24T21:20:23.878+0000

• Duration: 124 min 47 sec

• Commit: 49c5d5b

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Test	Results
Failed	0
Passed	4440
Skipped	311
Total	4751

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