fix error: Not default tab selected

Author: dungfv

src/bottomnavigationbar/bottomnavigationbar.ios.ts

@@ -1,6 +1,6 @@
 import { themer } from '@nativescript-community/ui-material-core';
 import { Application, Color, Screen, Utils, backgroundColorProperty } from '@nativescript/core';
-import { BottomNavigationBarBase, BottomNavigationTabBase,TitleVisibility,  activeColorCssProperty, badgeColorCssProperty, badgeTextColorCssProperty, inactiveColorCssProperty, tabsProperty, titleVisibilityProperty } from './bottomnavigationbar-common';
+import { BottomNavigationBarBase, BottomNavigationTabBase, TitleVisibility, activeColorCssProperty, badgeColorCssProperty, badgeTextColorCssProperty, inactiveColorCssProperty, tabsProperty, titleVisibilityProperty } from './bottomnavigationbar-common';
 
 @NativeClass
 class BottomNavigationBarDelegate extends NSObject {
@@ -140,10 +140,11 @@ export class BottomNavigationBar extends BottomNavigationBarBase {
             return tab;
         });
         this.nativeViewProtected.items = new NSArray({ array: bottomNavigationTabs });
+        let tabsArray = Utils.ios.collections.nsArrayToJSArray(this.nativeViewProtected.items)
 
         // TODO: this is for he v8 runtime. Should not have to need this setTimeout(), find better way.
         setTimeout(() => {
-            this.nativeViewProtected.selectedItem = this.nativeViewProtected.items[this.selectedTabIndex];
+            this.nativeViewProtected.selectedItem = tabsArray[this.selectedTabIndex];
         }, 0);
     }
 
@@ -174,7 +175,7 @@ declare class MDCBottomNavigationItemView extends UIView {
 export class BottomNavigationTab extends BottomNavigationTabBase {
     nativeViewProtected: UITabBarItem;
     createNativeView() {
-        let icon = this.getNativeIcon() ;
+        let icon = this.getNativeIcon();
         if (icon) {
             icon = icon.imageWithRenderingMode(UIImageRenderingMode.Automatic);
         }