(554545) Remove double logging

[MarkZuber]

Please pay special attention to changes made in LoggerCallbackTests.cs and AdalLoggerBase::Log() to ensure behavior is consistent with legacy.

[bgavrilMS]

While having a look at the MSALLogger, I noticed that one of the methods throws an exception - is this expected? If not, probably missing a unit test as well.. Please check ADALLogger as well. Otherwise the PR looks good!

public override void InfoPii(string messageWithPii, string messageScrubbed)
{
throw new NotImplementedException();
}

[bgavrilMS]

noPiiMsg [](start = 49, length = 8)

Tedious work, thanks for doing this! #ByDesign

[bgavrilMS]

[MarkZuber]

      While having a look at the MSALLogger, I noticed that one of the methods throws an exception - is this expected? If not, probably missing a unit test as well.. Please check ADALLogger as well. Otherwise the PR looks good!

public override void InfoPii(string messageWithPii, string messageScrubbed)
{
throw new NotImplementedException();
}
You may have been looking at an intermediary commit. I've re-reviewed the code and I don't see any NotImplementedExceptions being thrown within any of the loggers.