Make saveNotification instance method

Author: aurimasc

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

@@ -337,7 +337,7 @@ void performNotificationScheduling(int id, Notification.Builder notificationBuil
             Intent intent = buildNotificationIntent();
 
             if (intent != null) {
-                UnityNotificationManager.saveNotification(mContext, notificationBuilder.build());
+                saveNotification(notificationBuilder.build());
                 scheduleAlarmWithNotification(notificationBuilder, intent, fireTime);
             }
         }
@@ -487,9 +487,9 @@ private PendingIntent getBroadcastPendingIntent(int id, Intent intent, int flags
 
     // Save the notification intent to SharedPreferences if reschedule_on_restart is true,
     // which will be consumed by UnityNotificationRestartOnBootReceiver for device reboot.
-    protected static synchronized void saveNotification(Context context, Notification notification) {
+    synchronized void saveNotification(Notification notification) {
         String notification_id = Integer.toString(notification.extras.getInt(KEY_ID, -1));
-        SharedPreferences prefs = context.getSharedPreferences(getSharedPrefsNameByNotificationId(notification_id), Context.MODE_PRIVATE);
+        SharedPreferences prefs = mContext.getSharedPreferences(getSharedPrefsNameByNotificationId(notification_id), Context.MODE_PRIVATE);
         UnityNotificationUtilities.serializeNotification(prefs, notification);
     }