D18529: Rename Activities KCM icon

[Noah Davis]

ndavis added a dependent revision: D18532: Change icons for Activities 
dataengine and runner.

REPOSITORY
  R266 Breeze Icons

REVISION DETAIL
  https://phabricator.kde.org/D18529

To: ndavis, #vdg
Cc: kde-frameworks-devel, michaelh, ngraham, bruns