Throttle excessive calls to NM.notify()

This approach doesn't use IpcDataCache (which might be infeasible for posted notifications, since they change frequently) so, lacking precise information, it's heuristic-based. However, the thresholds are sufficiently large so that normal usage of the API shouldn't be affected.

Bug: 381875150
Test: atest NotificationManagerTest + existing CTS
Flag: android.app.nm_binder_perf_throttle_notify
Change-Id: Icdc969c0c646ef2222194bacb5a8486fe38e0498