How can I access angle data information for Sentinel-2 L2A?

Grid of solar zenith angles and grid of solar azimuth angles are accessible by names sunZenithAngles and sunAzimuthAngles, respectively, and can be used in a similar way as band values, e.g.:

return [sunAzimuthAngles/50];
return [sunZenithAngles/60];

There are also two grids named viewZenithMean and viewAzimuthMean that contains average viewing incidence angles (zenith and azimuth) across all bands and detectors. They can be used as, e.g.:

return [viewAzimuthMean/70];
return [viewZenithMean/80];