Resolve intermittent errors when preparing image
This resolved intermittent failures when using apt in Docker container caused by fragile httpredir.debian.org service that sometimes picks the mirror that responds incorrectly.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
This resolved intermittent failures when using apt in Docker container caused by fragile httpredir.debian.org service that sometimes picks the mirror that responds incorrectly.