Provide option to disable autocompletion

### Which @angular/* package(s) are relevant/related to the feature request?

_No response_

### Description

If you developing an angular web app in an dev container every time the container is created or rebuild and you are running the `ng` command for the first time, the angular cli asks:

> ? Would you like to enable autocompletion? This will set up your terminal so pressing TAB while typing Angular CLI commands will show possible options and autocomplete arguments. (Enabling autocompletion will modify
configuration files in your home directory.)

You can activate this "feature" but there is no way to disable it proactive.

You could run the command `ng config -g cli.completion.prompted true`but if this is the first execution of the angular cli this only lead to the question if I want to enable autocompletion. So this isn't a solution.

### Proposed solution

Because the user has the possibility to opt this feature out when the angular cli asks you if you want to enable the autocompletion and because there is an command to enable this without being asked there should also be to possibility to disable this feature with an command like

`ng completion disable`

### Alternatives considered

As an alternative you could also make the global configuration settings

```json
{
"cli": {
"completion": {
"prompted": true
}
}
}
```

also available in the `angular.json` file.

Start by tracing the Angular CLI completion command and the global cli.completion.prompted configuration described in the issue. Determine how the first-run prompt and completion enablement are handled, then add a supported disable path such as `ng completion disable`. Done means users can disable completion without being prompted again and the relevant CLI behavior is covered by tests.

Written by the indexing model from the issue text.