Add HTTP2 protocol to backend service

[emilymye]

Fixes hashicorp/terraform-provider-google#3627

---

[all]

[terraform]

Add HTTP2 protocol to backend service

[terraform-beta]

Add HTTP2 protocol to backend service

[ansible]

[inspec]

[modular-magician]

Hi! I'm the modular magician, I work on Magic Modules.
This PR seems not to have generated downstream PRs before, as of 65b0fe8.

Pull request statuses

No diff detected in terraform-google-conversion.

New Pull Requests

I built this PR into one or more new PRs on other repositories, and when those are closed, this PR will also be merged and closed.
depends: hashicorp/terraform-provider-google-beta#708
depends: hashicorp/terraform-provider-google#3631
depends: modular-magician/ansible#242
depends: modular-magician/inspec-gcp#156

[modular-magician]

Hi! I'm the modular magician, I work on Magic Modules.
I see that this PR has already had some downstream PRs generated. Any open downstreams are already updated to your most recent commit, 940e824.

Pull request statuses

terraform-provider-google-beta already has an open PR.
No diff detected in terraform-google-conversion.
terraform-provider-google already has an open PR.
Ansible already has an open PR.
InSpec already has an open PR.

New Pull Requests

I didn't open any new pull requests because of this PR.