Trigger certificate chooser when check box checked

For convenience.  Implemented in onCheckChanged().

As a consequence, onCheckChanged() must not be triggered when the instance
state is restored (would occur if the check box state was checked when
saved), otherwise the certificate chooser would pop up once the state was
restored.  Therefore, all listeners have been moved into
initializeViewListeners() which is invoked after the state has been
restored.

Because onCheckChanged() is no longer triggered in
onRestoreInstanceState(), updateViewVisibility() was implemented to
restore the view visibility.