Merge "Revert "Revert "Remove cutils threads.h header completely.""" into main am: c05fd258ee am: 37f0b26947

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

Change-Id: I31bc04ef04737443b1c19f9bb5158e2f234bbae1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>