Enable HAVE_MONOTONIC_CLOCK compiler flag

This will make D-Bus use monotonic clock instead of system time
for timeout calculation, which prevents issues when system time
changes while there is a pending call.

Bug: 25159392
TEST=Manual test on Brillo boards

Change-Id: I2f4f1ea4848b47efe10b56efe02b2c7c9b33f779
1 file changed