They owned 5% from 2013 to at least 2019: https://www.cnbc.com/2019/04/11/alphabet-uber-investment-sta...
I think they sold it in 2019 when their lockup expired, but I can only find "they're thinking of doing it" news (https://techcrunch.com/2019/10/03/ceo-david-krane-suggests-g...) and not an announcement.