Added custom navigationBarClass support to NavigationController

Sources/iOS/NavigationController.swift

@@ -70,6 +70,11 @@ open class NavigationController: UINavigationController {
     setViewControllers([rootViewController], animated: false)
   }
     
+    public init(rootViewController: UIViewController, navigationBarClass: Swift.AnyClass?) {
+        super.init(navigationBarClass: navigationBarClass, toolbarClass: nil)
+        setViewControllers([rootViewController], animated: false)
+    }
+  
   open override func viewWillAppear(_ animated: Bool) {
     super.viewWillAppear(animated)
     guard let v = interactivePopGestureRecognizer else {