Add support for the google_compute_service_attachment resource

[rileykarson]

Fixes hashicorp/terraform-provider-google#9062

Using ACCEPT_MANUAL and project(s) set causes a permadiff, I'm awaiting a response about that before moving forward

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)

`google_compute_service_attachment`

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 2 files changed, 378 insertions(+))
Terraform Beta: Diff ( 7 files changed, 1424 insertions(+), 4 deletions(-))
TF OiCS: Diff ( 8 files changed, 403 insertions(+))

[modular-magician]

I have triggered VCR tests based on this PR's diffs. See the results here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=191186"

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccBigtableAppProfile_bigtableAppProfileMulticlusterExample|TestAccBigtableAppProfile_bigtableAppProfileSingleclusterExample|TestAccComputeServiceAttachment_serviceAttachmentBasicExample|TestAccComputeServiceAttachment_serviceAttachmentExplicitProjectsExample|TestAccEventarcTrigger_transport You can view the result here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=191289"

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 2 files changed, 378 insertions(+))
Terraform Beta: Diff ( 6 files changed, 1423 insertions(+), 2 deletions(-))
TF OiCS: Diff ( 8 files changed, 403 insertions(+))

[modular-magician]

I have triggered VCR tests based on this PR's diffs. See the results here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=191372"

[modular-magician]

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

Diff report:

Terraform GA: Diff ( 2 files changed, 378 insertions(+))
Terraform Beta: Diff ( 6 files changed, 1423 insertions(+), 2 deletions(-))
TF OiCS: Diff ( 8 files changed, 403 insertions(+))

[modular-magician]

I have triggered VCR tests based on this PR's diffs. See the results here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=191376"

[slevenick]

Seems reasonable to me once ACCEPT_MANUAL works

[rileykarson]

Oh! That does now, that was 1f28c23 (#4855)

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccComputeServiceAttachment_serviceAttachmentBasicExample|TestAccComputeServiceAttachment_serviceAttachmentExplicitProjectsExample You can view the result here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=191378"

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccComputeServiceAttachment_serviceAttachmentBasicExample|TestAccComputeServiceAttachment_serviceAttachmentExplicitProjectsExample You can view the result here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=191388"