Rename s3 input to aws-s3 input

[kaiyan-sheng]

What does this PR do?

This PR is to rename Filebeat s3 input to aws-s3 input.
Closes elastic/integrations#488

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.

How to test this PR locally

1. Test the Filebeat aws-s3 input:

filebeat.inputs:
- type: aws-s3
  enabled: true
  queue_url: https://sqs.eu-central-1.amazonaws.com/428152502467/filebeat-aws-elb-test
  credential_profile_name: elastic-beats

This should start aws-s3 input with no error.

2. Test Filebeat filesets that use aws-s3 input:

./filebeat modules enable aws

and change modules.d/aws.yml to enable a fileset in aws module. For example:

- module: aws
  cloudtrail:
    enabled: true
    var.queue_url: https://sqs.us-east-1.amazonaws.com/428152502467/test-fb-ks
    var.credential_profile_name: elastic-beats

Then run Filebeat and you should see no error. If there are new logs going into the S3 which generates new SQS messages in test-fb-ks, you should also see the events in Elasticsearch.

[elasticmachine]

Pinging @elastic/integrations (Team:Platforms)

[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

• Build Cause: Pull request #23469 updated

• • Start Time: 2021-01-15T16:37:02.285+0000

• Duration: 51 min 49 sec

• Commit: e3a2beb

Test stats 🧪

Test	Results
Failed	0
Passed	6555
Skipped	578
Total	7133

💚 Flaky test report

Tests succeeded.

Expand to view the summary

Test stats 🧪

Test	Results
Failed	0
Passed	6555
Skipped	578
Total	7133

[elasticmachine]

Pinging @elastic/ingest-management (Team:Ingest Management)

[bmorelli25]

For the doc build, change this line:

https://github.com/elastic/beats/blame/18fb50493f6cd60eed1661caa3c4939de59db20e/filebeat/docs/filebeat-options.asciidoc#L79

It should be:

* <<{beatname_lc}-input-aws-s3>>

When I make this change the PR builds locally 🎉

[leehinman]

I think filebeat/docs/aws-credentials-examples.asciidoc and x-pack/filebeat/_meta/config/filebeat.inputs.reference.xpack.yml.tmpl need updating too.

otherwise looks great.

[kaiyan-sheng]

@leehinman Good catch! It's fixed now, thank you!