Clean up location permissions annotation

[LukasPaczos]

The permissions are only required when the location component's being enabled, not during activation.

@langsmith would it make sense to adjust the examples in the docs and the demo app?

[carstenhag]

In my opinion, it would be prettier to have a separate enableLocationComponent() method, in order to reinforce that you are changing something important. Similarly, activateLocationComponent() exists.

It seems unintuitive that setLocationComponentEnabled is a setter.