Refactor / update services members visibility and explicit inject

When implementing services in other platforms we override certain existing services to add custom minor custom implementation.

But we have two problems with this:

We can't access injected services when extending a service because they are all declared private. This means we have to inject the same service a second time and name it something else (storageService2 for example).

The second problem is that when extending a class that injects services via the constructor, the injection fails when there is no @inject(Service) annotation. I believe this is because the class method descriptor is lost when extending the class, but I'm not sure. I think it's safer to explicit annotate the arguments which also makes it consistent.

jwplayer / ott-web-app

Refactor / update services members visibility and explicit inject #590