Merge getOreoNotificationChannel into getNotificationChannel

Author: aurimasc

com.unity.mobile.notifications/Runtime/Android/Plugins/com/unity/androidnotifications/UnityNotificationManager.java

@@ -195,11 +195,12 @@ protected static String getSharedPrefsNameByChannelId(String id)
         return String.format("unity_notification_channel_%s", id);
     }
 
-    // Get a notification channel by id.
-    // This function will only be called for devices which are low than Android O.
     protected static NotificationChannelWrapper getNotificationChannel(Context context, String id) {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-            return UnityNotificationManagerOreo.getOreoNotificationChannel(context, id);
+            NotificationChannel ch = getNotificationManager(context).getNotificationChannel(id);
+            if (ch == null)
+                return null;
+            return notificationChannelToWrapper(ch);
         }
 
         SharedPreferences prefs = context.getSharedPreferences(getSharedPrefsNameByChannelId(id), Context.MODE_PRIVATE);

com.unity.mobile.notifications/Runtime/Android/Plugins/com/unity/androidnotifications/UnityNotificationManagerOreo.java

@@ -13,18 +13,6 @@ public UnityNotificationManagerOreo(Context context, Activity activity) {
         super(context, activity);
     }
 
-    protected static NotificationChannelWrapper getOreoNotificationChannel(Context context, String id) {
-        assert Build.VERSION.SDK_INT >= Build.VERSION_CODES.O;
-
-        List<NotificationChannelWrapper> channelList = new ArrayList<NotificationChannelWrapper>();
-
-        for (NotificationChannel ch : getNotificationManager(context).getNotificationChannels()) {
-            if (ch.getId() == id)
-                return notificationChannelToWrapper(ch);
-        }
-        return null;
-    }
-
     @Override
     public void deleteNotificationChannel(String id) {
         assert Build.VERSION.SDK_INT >= Build.VERSION_CODES.O;