Police are under local, not Federal jurisdicion.
Tthe Third Amendment hasn’t been “incorported” yet, it doesn’t apply to cops because they are local, not Federal.
Technically, you are correct. Except they do everything the feds say.
Why do you think we have seatbelt laws, child safety seat laws, uniform DWI laws with BAC levels dialed down to ridiculously low levels, etc., etc., ad nauseum.