No longer hydrate timezone from the server

After the implementation to start updating timezone changes on new sessions, hydrating timezone from the user refresh call will conflict if the timing between the update and refresh requests is not perfect. For example, imagine this scenario if we still hydrate this property:
1. On a new session, timezone detects as changed from US to UK. A property update is enqueued.
2. This request is sent and the refresh user call returns (which still contains timezone as US)
3. The SDK hydrates timezone as US
4. On the next session, timezone is detected as changed from US to UK.

Author: nan-li

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/user/internal/operations/impl/executors/RefreshUserOperationExecutor.kt

@@ -89,9 +89,8 @@ internal class RefreshUserOperationExecutor(
                 }
             }
 
-            if (response.properties.timezoneId != null) {
-                propertiesModel.timezone = response.properties.timezoneId
-            }
+            // No longer hydrate timezone from remote, set locally
+            propertiesModel.update()
 
             val subscriptionModels = mutableListOf<SubscriptionModel>()
             for (subscription in response.subscriptions) {