activity.js: use proper phrasing for singe [hour, minute, day]
activity.js: use proper phrasing for singe [hour, minute, day]

shlomif/rhizi,yuvadm/rhizi,Rhizi/rhizi,ozFri/rhizi,tlevine/rhizi,ozFri/rhizi,ozFri/rhizi,tlevine/rhizi,ozFri/rhizi,shlomif/rhizi,Rhizi/rhizi,shlomif/rhizi,yuvadm/rhizi,shlomif/rhizi,tlevine/rhizi,cben/rhizi,tlevine/rhizi,yuvadm/rhizi,cben/rhizi,Rhizi/rhizi,cben/rhizi,cben/rhizi,yuvadm/rhizi,Rhizi/rhizi