Change User State Method Synchronization

• In the previous commit, I wanted to explicitly use a sync lock object for different methods to synchronize on, to allow more fine-grained control over what parts of methods get synchronized
• However, I mistakenly left out a method called getToSyncUserState().
• This commit removes the method synchronization and synchronizes on the syncLock, an instance property that other methods also use to synchronize on.

Author: Nightsd01

OneSignalSDK/onesignal/src/main/java/com/onesignal/UserStateSynchronizer.java

@@ -119,9 +119,11 @@ protected JSONObject generateJsonDiff(JSONObject cur, JSONObject changedTo, JSON
         }
     }
 
-    protected synchronized UserState getToSyncUserState() {
-        if (toSyncUserState == null)
-            toSyncUserState = newUserState("TOSYNC_STATE", true);
+    protected UserState getToSyncUserState() {
+        synchronized (syncLock) {
+            if (toSyncUserState == null)
+                toSyncUserState = newUserState("TOSYNC_STATE", true);
+        }
 
         return toSyncUserState;
     }