chore(dropdown): avoid toggling class on first load
chore(dropdown): avoid toggling class on first load

- Avoid toggling class on first load of directive

Closes #5341

fpipita/bootstrap,christor/bootstrap,caoruiy/bootstrap,angular-ui/bootstrap,shootermv/bootstrap,burlhock/bootstrap,BookingBug/bootstrap,wesleycho/bootstrap,Foxandxss/bootstrap,benhalverson/bootstrap,Servoy/bootstrap,Kpler/bootstrap,BookingBug/bootstrap,vfiles/bootstrap,RobJacobs/bootstrap,icfantv/bootstrap,burlhock/bootstrap,infowrap/bootstrap,mabi/bootstrap,benhalverson/bootstrap,angular-ui/bootstrap,caoruiy/bootstrap,Kpler/bootstrap,Foxandxss/bootstrap,292388900/bootstrap,shootermv/bootstrap,Servoy/bootstrap,infowrap/bootstrap,christor/bootstrap,benhalverson/bootstrap,RobJacobs/bootstrap,byronigoe/bootstrap,benhalverson/bootstrap,wesleycho/bootstrap,292388900/bootstrap,fpipita/bootstrap,looker/bootstrap,mabi/bootstrap,byronigoe/bootstrap,icfantv/bootstrap,vfiles/bootstrap,looker/bootstrap