Merge "Remove sub-includes from libcutils/threads.h" into main am: a981d589...

Merge "Remove sub-includes from libcutils/threads.h" into main am: a981d589 am: bf51390a am: 40cff3af am: 9a04ae3a am: 5326eaab

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2675702



Change-Id: I64ee25ff7bc5f96b948580005544bd4f4a31686f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>