[Feature] Add support for Unified host without experimental flag

[tanmay-db]

What changes are proposed in this pull request?

• Add support for unified hosts without experimental flag.
• [Breaking] Remove experimental flag. Given we didn't document experimental flag, it probably should be OK to remove.

How is this tested?

• Unit tests
• Existing integration tests
• Passing Manual E2E tests on spog host.
  • Note :We should integrate unified host test infra with CI then we can add these as part of the PR. This isn't part of this PR.

[github-actions]

If integration tests don't run automatically, an authorized user can run them manually by following the instructions below:

Trigger:
go/deco-tests-run/sdk-go

Inputs:

• PR number: 1403
• Commit SHA: 9b4a4dcddeea00ad70b3cf218a869bcbc4e52d45

Checks will be approved automatically on success.