To allow individual notifications to be
marked as read/unread or moderated,
bundles are created by grouping associated
notifications when they are fetched for display
instead of when they are created.
From a product perspective, this change doesn't
introduce moderation or expandable bundles but
it counts each individual notifications.
For instance, the bundled notification
"3 new topics on PageA" now counts as 3
notifications.
Bug: T93673
Bug: T120153
Change-Id: Iacd098573efd92bb1e3fcd7da4cd40cea9522f15