android: add missing feature tags.

Adding the CAMERA and RECORD_AUDIO permissions implicitely makes some
features a hard requirement for the app.
By adding these features in the .pro file, androiddeployqt will mark
them as unrequired in the final package.

Change-Id: Ie9357d05626cb12272001d63b04e230737fbf1bc
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>