Add preferences-system-bluetooth-battery to preferences.svgz
Summary: It's exactly the same as the regular 32px bluetooth icon in this file, but D17346 needs it.
Reviewers: VDG, Plasma, broulik, ngraham
Reviewed By: VDG, Plasma, broulik, ngraham
Subscribers: kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D17505