[containments/desktop] Use new colorful filter icon

Summary: {F7431292}

Test Plan: Open the desktop configuration dialog.

Reviewers: #plasma, #vdg, ngraham

Reviewed By: #vdg, ngraham

Subscribers: plasma-devel, #vdg, #plasma

Tags: #plasma

Maniphest Tasks: T10165

Differential Revision: https://phabricator.kde.org/D24228