Solid-device-automounter/kcm: Enable/Disable columns automount...

Solid-device-automounter/kcm: Enable/Disable columns automount onLogin/onAttached depending on corresponding checkbox

Summary: To make clear to the user what automount options imply.

Test Plan:
Before:

{F8049400}

After:
{F8049404}

{F8049407}

Reviewers: #plasma, ervin, ngraham, broulik, bport, crossi

Reviewed By: ervin

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D27057