Fix wrong KCM device icon for specific form factors
Summary:
The KCM did not know how different form factors should be displayed. The applet uses a functiun in "icon.js" to find out which icon to use. I have ported this over to the KCM.
Related: D24161
Test Plan:
Connect phone via Bluetooth and play music.
Now: "phone" icon appears
Before: "audio-card" icon appears,
Reviewers: VDG, Plasma, ngraham, GB_2
Reviewed By: VDG, ngraham
Subscribers: Plasma, plasma-devel, VDG
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D24289