http://admission.universityofcalifornia.edu/campuses/files/freshman-profiles/freshman_profile_la.pdf
This shows the UCLA freshman profile, including the # of AP/Honors classes - as you can see, your odds do go up with 15+ but, as noted above a high GPA/SAT are the first and foremost (a rigorous schedule too) but high GPA beats too rigorous of a schedule. To be competitive for UCLA, you need near perfect grades (4…25 UC GPA) and a near perfect SAT/ACT. Not sure where you stand right now but, a super rigorous sr schedule won’t improve your chances if your stats are sub par.
If you were my kid, I’d seriously consider backing off your Sr sched. For most kids, Sr year is a real time compressed roller-coaster - These boards are full of kids who blew an AP Calc class and had admissions rescinded. IMHO, taking 3 APs instead of 5 Sr year won’t impact your UC admission either way.
Good luck