Feature name instead of id is recorded in the image metadata

[alexdima]

Testing #7248

• basically all the CLI steps in Test: Dev container image metadata #7248
• Looking at the output of docker inspect test-base-image | grep metadata after formatting:

[
    {
        "id": "terraform",
        "customizations": {
            "vscode": {
                "extensions": [
                    "HashiCorp.terraform",
                    "ms-azuretools.vscode-azureterraform"
                ],
                "settings": {
                    "terraform.languageServer.enable": true,
                    "terraform.languageServer.args": [
                        "serve"
                    ],
                    "azureTerraform.terminal": "integrated"
                }
            }
        }
    },
    {
        "postAttachCommand": "echo 'Hello from the postAttachCommand in the base image!'",
        "customizations": {
            "vscode": {
                "extensions": [
                    "chrmarti.regex"
                ]
            }
        }
    }
]

I would have expected the id of the first element in the JSON array to be ghcr.io/devcontainers/features/terraform or ghcr.io/devcontainers/features/terraform:1.0.5 instead of terraform.