Merge "Revert "Revert "Remove cutils threads.h header completely.""" into main...

Merge "Revert "Revert "Remove cutils threads.h header completely.""" into main am: c05fd258 am: 37f0b269 am: 604233aa

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2713394



Change-Id: I40fa185bf713b6a95aaaf7435f22598938e666bc
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>