[notifications] Minor fixes

ios/RNFirebase/notifications/RNFirebaseNotifications.m

@@ -1,6 +1,7 @@
 #import "RNFirebaseNotifications.h"
 
 #if __has_include(<FirebaseMessaging/FIRMessaging.h>)
+#import "RNFirebaseEvents.h"
 #import <React/RCTUtils.h>
 
 #if defined(__IPHONE_10_0) && __IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_10_0
@@ -372,7 +373,7 @@ RCT_EXPORT_METHOD(scheduleNotification:(NSDictionary*) notification
 }
 
 - (NSArray<NSString *> *)supportedEvents {
-    return @[];
+    return @[NOTIFICATIONS_NOTIFICATION_RECEIVED];
 }
 
 + (BOOL)requiresMainQueueSetup

lib/modules/notifications/Notification.js

@@ -2,6 +2,7 @@
  * @flow
  * Notification representation wrapper
  */
+import { Platform } from 'react-native';
 import AndroidNotification from './AndroidNotification';
 import IOSNotification from './IOSNotification';
 import { generatePushID, isObject } from '../../utils';
@@ -11,10 +12,10 @@ import type { NativeIOSNotification } from './IOSNotification';
 import type { Schedule } from './';
 
 type NativeNotification = {|
-  android: NativeAndroidNotification,
+  android?: NativeAndroidNotification,
   body: string,
   data: { [string]: string },
-  ios: NativeIOSNotification,
+  ios?: NativeIOSNotification,
   notificationId: string,
   schedule?: Schedule,
   sound?: string,
@@ -128,10 +129,10 @@ export default class Notification {
     }
 
     return {
-      android: this._android.build(),
+      android: Platform.OS === 'android' ? this._android.build() : undefined,
       body: this._body,
       data: this._data,
-      ios: this._ios.build(),
+      ios: Platform.OS === 'ios' ? this._ios.build() : undefined,
       notificationId: this._notificationId,
       sound: this._sound,
       subtitle: this._subtitle,