Clean up IAM Scopes in the documentation

[upodroid]

If this PR is for Terraform, I acknowledge that I have:

• Searched through the issue tracker for an open issue that this either resolves or contributes to, commented on it to claim it, and written "fixes {url}" or "part of {url}" in this PR description. If there were no relevant open issues, I opened one and commented that I would like to work on it (not necessary for very small changes).
• Generated Terraform, and ran make test and make lint to ensure it passes unit and linter tests.
• Ensured that all new fields I added that can be set by a user appear in at least one example (for generated resources) or third_party test (for handwritten resources or update tests).
• Ran relevant acceptance tests (If the acceptance tests do not yet pass or you are unable to run them, please let your reviewer know).
• Read the Release Notes Guide before writing my release note below.

Release Note Template for Downstream PRs (will be copied)

[modular-magician]

Hello! I am a robot who works on Magic Modules PRs.

I have detected that you are a community contributor, so your PR will be assigned to someone with a commit-bit on this repo for initial review.

Thanks for your contribution! A human will be with you soon.

@melinath, please review this PR or find an appropriate assignee.

[upodroid]

This issue should be closed hashicorp/terraform-provider-google#1943

[upodroid]

Follow up from #4273

[upodroid]

@rileykarson while i'm cleaning up legacy scopes, can i remove compute, devstorage and clouddns in a minor release from the snippet below given that cloud-platform supercedes them?

https://github.com/hashicorp/terraform-provider-google/blob/179ede2188a1c16c3d17dd7e3099b616297000d8/google/config.go#L219

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 8 files changed, 48 insertions(+), 119 deletions(-))
Terraform Beta: Diff ( 8 files changed, 48 insertions(+), 119 deletions(-))

[rileykarson]

@upodroid: Can you file an issue? I don't want to change the declared list of scopes outside of a major version, particularly if we're removing any.

[rileykarson]

drive-by: This + the node pool example being removed are intentional and should be kept, even if they don't fit the best practices for configuring the resource. While we'd prefer users configure resources using the recommended setups, I'd rather we provide clear documentation on what alternatives look like vs forcing users to experiment themselves.

[upodroid]

I'll revert this change for both resources.

[upodroid]

The GKE resource is such a mess. There are so many open breaking change issues for it.

[rileykarson]

It's a busy resource!

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 8 files changed, 68 insertions(+), 78 deletions(-))
Terraform Beta: Diff ( 9 files changed, 69 insertions(+), 79 deletions(-))

[melinath]

LGTM for the most part - I have a few questions, and one suggested change to the new standard language explaining service account usage.

[melinath]

lgtm - thanks!

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 8 files changed, 68 insertions(+), 78 deletions(-))
Terraform Beta: Diff ( 8 files changed, 68 insertions(+), 78 deletions(-))

[melinath]

@upodroid I ran into an issue where using the service account names in the new documentation causes an error because of the use of _ instead of -. Is there any chance you would be able to put together a follow-up PR switching those over?

Error: "account_id" ("service_account_id") doesn't match regexp "^[a-z](?:[-a-z0-9]{4,28}[a-z0-9])$"

[upodroid]

Hmm, which example was that?

[upodroid]

nvm, underscores are illegal in service account names