notificationIcon property
Notification small-icon drawable resource id used for AppDNA push
notifications (Android only; iOS ignores it). 0/unset falls
back to manifest meta-data then the app icon.
Caveat: this is an Android R.drawable.* resource id (an int) — a
pure-Dart host has no such id, so it is only useful when a native Android
layer supplies it. Bridged for full surface parity.
Implementation
final int? notificationIcon;