Support navigatorButtons

android/app/src/main/java/com/reactnativenavigation/activities/SingleScreenActivity.java

         setContentView(R.layout.single_screen_activity);
         mToolbar = (RnnToolBar) findViewById(R.id.toolbar);
 
-        Screen screen = (Screen) getIntent().getSerializableExtra(EXTRA_SCREEN);
+        final Screen screen = (Screen) getIntent().getSerializableExtra(EXTRA_SCREEN);
         mNavigatorId = screen.navigatorId;
 
         mScreenStack = new ScreenStack(this);
         contentFrame.post(new Runnable() {
             @Override
             public void run() {
-                setupToolbar(getCurrentScreen());
+                setupToolbar(screen);
             }
         });
     }

android/app/src/main/java/com/reactnativenavigation/core/objects/Screen.java

     public static final String KEY_NAVIGATOR_ID = "navigatorID";
     public static final String KEY_NAVIGATOR_EVENT_ID = "navigatorEventID";
     private static final String KEY_ICON = "icon";
+    private static final String KEY_NAVIGATOR_BUTTONS = "navigatorButtons";
     private static final String KEY_RIGHT_BUTTONS = "rightButtons";
     private static final String KEY_TOOL_BAR_STYLE = "navigatorStyle";
     private static final String KEY_STATUS_BAR_COLOR = "statusBarColor";
 
     private ArrayList<Button> getButtons(ReadableMap screen) {
         ArrayList<Button> ret = new ArrayList<>();
-        if (screen.hasKey(KEY_RIGHT_BUTTONS)) {
-            ReadableArray rightButtons = screen.getArray(KEY_RIGHT_BUTTONS);
+        if (hasButtons(screen)) {
+            ReadableArray rightButtons = getRightButtons(screen);
             for (int i = 0; i < rightButtons.size(); i++) {
                 ret.add(new Button(rightButtons.getMap(i)));
             }
         return ret;
     }
 
+    private boolean hasButtons(ReadableMap screen) {
+        return screen.hasKey(KEY_RIGHT_BUTTONS) || screen.hasKey(KEY_NAVIGATOR_BUTTONS);
+    }
+
+    private ReadableArray getRightButtons(ReadableMap screen) {
+        return screen.hasKey(KEY_RIGHT_BUTTONS) ? screen.getArray(KEY_RIGHT_BUTTONS) :
+                screen.getMap(KEY_NAVIGATOR_BUTTONS).getArray(KEY_RIGHT_BUTTONS);
+    }
+
     public Drawable getIcon(Context ctx) {
         return IconUtils.getIcon(ctx, icon);
     }

src/platformSpecific.android.js

   Object.assign(screen, Screen.navigatorButtons);
 
   // Get image uri from image id
-  if (screen.rightButtons) {
-    screen.rightButtons.forEach(function(button) {
+  const rightButtons = screen.rightButtons ? screen.rightButtons : screen.navigatorButtons ?
+    screen.navigatorButtons.rightButtons : null;
+  if (rightButtons) {
+    rightButtons.forEach(function(button) {
       if (button.icon) {
         const icon = resolveAssetSource(button.icon);
         if (icon) {