[Metricbeat] Add integration tests for GCP

[kaiyan-sheng]

We want to improve our coverage with integration tests for googlecloud module using real GCP services. Similar to terraform scenario in Filebeat for ELBs, we can create scenarios for deploying and destroying testing services in GCP using Terraform for individual metricsets.

• create terraform scenario for each metricset in googlecloud module
• make sure service is up and running before trying to query for monitoring metrics
• test metadata collection for compute metricset

[elasticmachine]

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

[endorama]

Work on adding required test infrastructure for running system/integration test is being performed in integrations repo. I plan to understand how to leverage the same terraform code to test beats and integration package, as the required infrastructure should be the same.

PRs adding tests to gcp integration package:

• GCP package billing datastream tests integrations#2312

[botelastic]

Hi!
We just realized that we haven't looked into this issue in a while. We're sorry!

We're labeling this issue as Stale to make it hit our filters and make sure we get back to it as soon as possible. In the meantime, it'd be extremely helpful if you could take a look at it as well and confirm its relevance. A simple comment with a nice emoji will be enough :+1.
Thank you for your contribution!