In searches you should err on the side of broadness. If you cut it down to just 'whitening', as you can see from the snippets as well, there are plenty of hits. You may not like whitening, but it does still seem to be common.
If you want some better data than unreliable searches, go download pretrained models for popular architectures and popular frameworks and look at the input pipelines for them. You'll find that whitening is absolutely not common for image classification/detection today (yes, there are still some cases where it is used, but typically on smaller datasets where you can't get that invariance from data, which is the way you prefer it to be - if one class actually is more likely to be present in dark images, you don't want to kill that information).