Bug 874769 - [Gaia] Use new WebAPI to access card state related attribute/event

Please see [bug 874769](https://bugzilla.mozilla.org/show_bug.cgi?id=874769).

In [bug 874744](https://bugzilla.mozilla.org/show_bug.cgi?id=874744), we move cardState related attribute/event from mozMobileConnection to mozIccManager. This pull request is to do corresponding changes in Gaia side.

Thanks