Apply double check pattern to avoid race condition in LoggingService

[YuliiaKovalova]

Fixes: https://dev.azure.com/devdiv/DevDiv/_workitems/edit/2320135/

Context

Reset() method invocation sometimes causes exception System.IO.IOException: 'The handle is invalid.'.
Very likely it happens on application shutdown.
The assumption is:

• ShutdownComponent starts and gets the _lockObject
• It cleans up/disposes the events
• Meanwhile our logging thread is trying to use those same events without checking _lockObject in context of StartLoggingEventProcessing()

Changes Made

To resolve this issue, the double-check pattern was implemented for the event fields.
This double-check approach prevents the 'invalid handle' exception from occurring during the race condition between component shutdown and the execution of the logging thread.

Testing

N/A

[rainersigwald]

I don't think I understand how this helps. Isn't there still a race between thread 1 seeing that it's non-null and calling into it and thread 2 calling Dispose()?