Change categories in AWS package

[kaiyan-sheng]

What does this PR do?

This PR is to remove network and security categories at the package level for AWS and add them into each policy template.

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• If I'm introducing a new feature, I have modified the Kibana version constraint in my package's manifest.yml file to point to the latest Elastic stack release (e.g. ^7.13.0).

Related issues

• Closes Revisit AWS categories  #1342

[elasticmachine]

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Build stats

• Start Time: 2021-07-27T21:20:49.710+0000

• Duration: 17 min 35 sec

• Commit: 5cb8a73

Test stats 🧪

Test	Results
Failed	0
Passed	247
Skipped	0
Total	247

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[leehinman]

I think we want security category on:

• cloudtrail
• s3
• vpcflow

[leehinman]

LGTM