[analysis_server] Improve comments for watch/events on File and Folders
[analysis_server] Improve comments for watch/events on File and Folders

Change-Id: Ied0369420651604aeaa44f0052172e868cbd6fbf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/228561
Reviewed-by: Konstantin Shcheglov <09e4d7516628963212bf4aace2f97603d2b706e4@google.com>
Commit-Queue: Konstantin Shcheglov <09e4d7516628963212bf4aace2f97603d2b706e4@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk