[Filebeat] Rename googlecloud module to gcp module

[kaiyan-sheng]

What does this PR do?

This PR is to rename googlecloud module in Filebeat to gcp module.
In this PR:

• rename googlecloud module name to gcp
• added an alias to allow the old name googlecloud to continue working
• keeping field names the same(googlecloud.*) till 8.0.

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

• Relates Fix inconsistency of GCP Filebeat/Metricbeat names #19467

[elasticmachine]

Pinging @elastic/integrations-platforms (Team:Platforms)

[kaiyan-sheng]

@jsoriano I added https://github.com/kaiyan-sheng/beats/blob/rename_googlecloud_fb/x-pack/filebeat/module/googlecloud/module.yml similar to apache2 -> apache. I thought this would avoid making this a breaking change. But when I ran ./filebeat modules list, I only see the new gcp module. So even with the googlecloud/module.yml, this will still be a breaking change?

[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 #22214 updated]

• Start Time: 2020-11-24T14:52:32.611+0000

• Duration: 43 min 20 sec

Test stats 🧪

Test	Results
Failed	0
Passed	4502
Skipped	562
Total	5064

💚 Flaky test report

Tests succeeded.

Expand to view the summary

Test stats 🧪

Test	Results
Failed	0
Passed	4502
Skipped	562
Total	5064

[elasticmachine]

💚 Flaky test report

Tests succeeded.

Expand to view the summary

Test stats 🧪

Test	Results
Failed	0
Passed	4503
Skipped	561
Total	5064

[kaiyan-sheng]

CI failure doesn't seem to be related. I created a separate issue for it: #22561

[andrewkroh]

LGTM. Can you please add to the description that an alias was added to allow the old name to continue working. And can you please open an issue so that the detection-rules can account for the event.dataset change (see https://github.com/elastic/detection-rules/search?q=googlecloud).

[kaiyan-sheng]

@andrewkroh Done, thank you for the review! Here is the issue: elastic/detection-rules#627