Revert "Revert "Remove cutils threads.h header completely.""

This reverts commit c37838eec8d7b5bcec74e8293a0bdb655991a4e7.

Reason for revert: b/296247274 root-cause fixed

Change-Id: I859e7500a1dd09e3a66986cda9e62adf5d7a524a
2 files changed