I wanted to chip in to say that IMHO you are on the right track looking at Applied Math as a potential, non-impacted major, particularly if you are aiming for Cal. Just be aware that you won’t exit with a degree in CS (at least not there) - it’s not like it’s a back door, though I believe you could minor in Data Science along with the AM major at Cal.
For a time my student was looking into this possibility. I think you have a very good chance at many excellent UC’s, but a better shot at one of the top ones via the Applied Math route, if that is your genuine interest, particularly if you have taken (and done well in) advanced math courses, better odds than CS or DS. Good luck!