Solid-device-automounter/kcm: correctly update automountOn
Test Plan:
Open kcmshell5 device_automounter_kcm
Play with the checkbox "Automatically mount..." and see that the corresponding columns below are enabled/disabled.
Reviewers: bport, Plasma, ervin, crossi, hchain
Reviewed By: ervin
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D27971