Merge pull request #1736 from OneSignal/user-model/raw-payload

[User Model] Expose `INotification.rawPayload`

Author: brismithers

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/notifications/INotification.kt

@@ -132,6 +132,12 @@ interface INotification {
      */
     val groupedNotifications: List<INotification>?
 
+    /**
+     * The raw payload of the notification that can into the device. This should only be used to
+     * access any data that is not yet represented in a property.
+     */
+    val rawPayload: String?
+
     /**
      * Create a mutable copy of this notification. Typically used in [IRemoteNotificationReceivedHandler]
      * or [INotificationWillShowInForegroundHandler] to modify an incoming notification prior to it

OneSignalSDK/onesignal/notifications/src/main/java/com/onesignal/notifications/internal/Notification.kt

@@ -51,7 +51,7 @@ open class Notification : INotification {
     override var sentTime: Long = 0
     override var ttl = 0
 
-    var rawPayload: String? = null
+    override var rawPayload: String? = null
 
     constructor() {}
     constructor(payload: JSONObject, time: ITime) : this(null, payload, 0, time) {}