An expanded notification includes:
1. A content title: A brief headline for the notification
2. An app name: The name of the app automatically appears in the notification.
3. An app icon: A small two-dimensional representation of your app's identity. It appears in monochrome in the status bar. If your app sends many notifications, you may replace your app's identity icon with a symbol that reflects the content type. For example, Google Now uses a cloud icon for weather notifications.
4. Content text: Supporting information
5. A big picture (optional): The big picture template places an image here.
6. Inline action: If you have a primary action in a collapsed notification, you should add the same action here.
7. Smart replies: If the notification is MessagingStyle, the system can show smart suggestions
8. Action drawer: Add any remaining notification actions in this area. The user can swipe up or tap the overflow icon to open the drawer.