bionic now defines _POSIX_MONOTONIC_CLOCK.

Change-Id: I0ccc29aa3701d74d6957892665c16a8f40cb2c42
Merge "bionic now defines _POSIX_MONOTONIC_CLOCK."
Revert "net: networking optimizations"

This reverts commit 5fbe95affc8eeed93c678b1d271f64dcc4dd919b.
Merge remote-tracking branch 'android/master' into HEAD