MOBILE-4215 android: Request notification permission on start

src/core/services/local-notifications.ts

@@ -71,9 +71,8 @@ export class CoreLocalNotificationsProvider {
     async initialize(): Promise<void> {
         await CorePlatform.ready();
 
-        if (!this.isAvailable()) {
-            return;
-        }
+        // Request permission when the app starts.
+        LocalNotifications.requestPermission();
 
         // Listen to events.
         this.triggerSubscription = LocalNotifications.on('trigger').subscribe((notification: ILocalNotification) => {