Use correct timestamps of events for logging.

Currently when WM detects certain events, it will notify the logger
of these events asynchronously and logger uses the timestamp at which it
gets notified to log these events. It's possible that the delay between
when the event actually occurs and when the logger gets notified could be
large. So for better accuracy, WM should also pass on the event timestamp
to the logger.

Bug: 62375480
Test: Triggered sysui_multi_action event logs and verified that
      APP_TRANSITION_DELAY_MS is less than APP_TRANSITION_WINDOWS_DRAWN_DELAY_MS.
Test: When the system is not busy, the timestamps we used to log earlier
      and timestamps we log with this change are almost same.
Change-Id: I5f62654a6b7f179d821c0082b180246c8a569df1