NotifCollection.dismissNotifications now takes EntryWithDismissStats instead of Pair

The change from Pair is unflagged, but the creation of copyForEntry is flagged.

Bug: 355967751
Flag: EXEMPT unflaggable readability type change
Flag: com.android.systemui.notifications_dismiss_pruned_summaries
Test: atest NotifCollectionTest
Change-Id: If4da4caec7a02782ea23bade5ab452fd58cae633