androidenv: Manually update missing packages

Improvement: Use nix-shell for fetch.sh

androidsdk{,_extras}:
- Update to 7.1.1

google_apis_25 is missing after fetch.sh due to an error in addon.xml
(upsteam bug).

Addons:
- Add google_apis_25
- Update google_play_services (v8_rc41 -> v11_rc16)