This commit replaces the old and slow `ReflectiveInjector` that was
deprecated in v5 with the new `Injector`. Note: This change was only
done in the spec files inside the `aio` folder.
While changing this, it was not possible to directly use `Injector.get`
to get the correct typing for the mocked classes. For example:
```typescript
locationService = injector.get<TestLocationService>(LocationService);
```
Fails with:
> Argument of type 'typeof LocationService' is not assignable to parameter
of type 'Type<TestLocationService> | InjectionToken<TestLocationService> |
AbstractType<TestLocationService>'.
Type 'typeof LocationService' is not assignable to type 'Type<TestLocationService>'.
Property 'searchResult' is missing in type 'LocationService' but required in type
'TestLocationService'.
Therefore, it was necessary to first convert to `unknown` and then to
`TestLocationService`.
```typescript
locationService = injector.get(LocationService) as unknown as TestLocationService;
```
PR Close#38408
175c79d1d8