Pull non-generic Settings icons from Adwaita set to the panels themselves.
Adwaita icon theme is carrying along several icons that are specific to the Settings panels which we'd like to deprecate from the set and move over to the panels themselves--given the Multitasking panel is already one that is shipping its icon along with the panel it's probably a good idea that the others follow suit.
To note this only means the icons that represent the panels themselves--that show in the sidebar for instance--and not things that are status icons.
Edited by Sam Hewitt