refactor(migrations): useFactory in provide-initializer migration - #58493

…8493)

The following provider:

```ts
{
  provide: APP_INITIALIZER,
  useFactory: (initService: InitService) => {
    return () => initService.init()
  },
  deps: [InitService],
  multi: true
}
```

was migrated into:

```ts
provideAppInitializer(() => { return ((initService: InitService) => {
  return () => initService.init()
})(inject(InitService)); })
```

This doesn't compile because there is an extra function:

```
✘ [ERROR] TS2345: Argument of type '() => () => void' is not assignable to parameter of type '() => void | Observable<unknown> | Promise<unknown>'.
  Type '() => void' is not assignable to type 'void | Observable<unknown> | Promise<unknown>'. [plugin angular-compiler]

    src/app/app.config.ts:7:26:
      7 │ ...ovideAppInitializer(() => { return ((initService: InitService) => {
```

It now migrates the provider into:

```ts
provideAppInitializer(((initService: InitService) => {
  return () => initService.init()
})(inject(InitService)))
```

PR Close #58493