Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
This backports https://github.com/nodejs/node/commit/d33b3d10860d31cbb8d63fd8f6e93555d8cd1c88 and https://github.com/nodejs/node/commit/0584aeb30a97d8ca81f242f4ddc05a0c6f9b7684 to v6.x-staging.