Fixes titleBarDisabledButtonColor (#490)

android/app/src/main/java/com/reactnativenavigation/params/TitleBarButtonParams.java

             color = titleBarButtonColor;
         }
     }
+
+    public StyleParams.Color getColor() {
+        if (enabled) {
+            return color;
+        }
+        return disabledColor.hasColor() ? disabledColor : AppStyle.appStyle.titleBarDisabledButtonColor;
+    }
 }

android/app/src/main/java/com/reactnativenavigation/params/parsers/TitleBarButtonParamsParser.java

         }
         result.color = getColor(bundle, "color", AppStyle.appStyle.titleBarButtonColor);
         result.disabledColor =
-                getColor(bundle, "disabledColor", AppStyle.appStyle.titleBarDisabledButtonColor);
+                getColor(bundle, "titleBarDisabledButtonColor", AppStyle.appStyle.titleBarDisabledButtonColor);
         result.showAsAction = parseShowAsAction(bundle.getString("showAsAction"));
         result.enabled = bundle.getBoolean("enabled", true);
         result.hint = bundle.getString("hint", "");

android/app/src/main/java/com/reactnativenavigation/views/TitleBarButton.java

 
     protected final Menu menu;
     protected final View parent;
-    protected TitleBarButtonParams buttonParams;
+    TitleBarButtonParams buttonParams;
     @Nullable protected String navigatorEventId;
 
     TitleBarButton(Menu menu, View parent, TitleBarButtonParams buttonParams, @Nullable String navigatorEventId) {
         return item;
     }
 
-
     private void setIcon(MenuItem item) {
         if (hasIcon()) {
             item.setIcon(buttonParams.icon);
 
     private void setTextColorForFoundButtonViews(ArrayList<View> outViews) {
         for (View button : outViews) {
-            ((TextView) button).setTextColor(buttonParams.color.getColor());
+            ((TextView) button).setTextColor(buttonParams.getColor().getColor());
         }
     }