Polish the lock contention logging.

- Make the code compilable.
- Surround the code with kLogLockContentions instead of #ifdef CONTENTION_LOGGING.
- Dump contended locks before never-contended locks for better log readability.
- Change the wait time unit from ms to us for better precision.

Bug: 9986464
Change-Id: I121c6ccf4424d3e0339b0dcd25e18976b41fe4f3
3 files changed