prevent looping calls to setIcon/setName

Activity no longer sets the activity name, icon, etc. that is the job of kactivitymanagerd,
perhaps via the activities DataEngine.

on activity creation, it was possible to have the icon set by Activity .. which would then call
setIcon on the KAMD activity .. which would then update Activity. which would then call .. etc.

tested creation of new activities, changing icons, etc. and all is well

bug reporters: please confirm

BUG:313319