Update ANCM file monitoring to hopefully avoid unneeded shutdowns

[BrennanConroy]

Hoping it fixes issues like #55939 where it looks like a phantom app_offline.htm file is seen by ANCM which causes the app to shutdown.

There were three specific issues found in the code:

1. m_detectedAppOffline wasn't initialized, so it could have any value, if it was true and there was a file notification then we'd trigger an app shutdown due to "detecting" app_offline
2. We just assumed if cbCompletion (now bytesTransferred) was 0 that app_offline was added to the directory. That's not really a good assumption, so changed it to manually check for app_offline
3. Any file or directory name that is a subset of app_offline.htm (e.g. app_o) would be detected as app_offline.htm

Also updated what file changes we look for to not include FILE_NOTIFY_CHANGE_SECURITY and FILE_NOTIFY_CHANGE_ATTRIBUTES (ref) to hopefully minimize the likelihood of getting bytesTransferred == 0 and it just seems like extra work when we aren't interested in those events.

[mgravell]

looks reasonable to me

[amcasey]

m_detectedAppOffline wasn't initialized

Are we not running a static analyzer to catch stuff like this?

[BrennanConroy]

m_detectedAppOffline wasn't initialized

Are we not running a static analyzer to catch stuff like this?

That's going to be another PR, because we definitely should be and I was working on adding it, but it added way too many warnings for this PR.