Merge "Revert "Remove cutils threads.h header completely."" into main am: ef2cae13e8 am: 996bc30a27 am: d79550d8fe am: 75ad5d8738

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2712413

Change-Id: Ibddddd451936005090420de8d928585646bb8b1e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>