Update the document for tabsStyle in Android (#1869)

* Update the comment for tabsStyle in Android

* for -> on

* Update top-level-api.md

docs/top-level-api.md

@@ -50,10 +50,10 @@ Navigation.startTabBasedApp({
     }
   ],
   tabsStyle: { // optional, add this if you want to style the tab bar beyond the defaults
-    tabBarButtonColor: '#ffff00', // optional, change the color of the tab icons and text (also unselected)
-    tabBarSelectedButtonColor: '#ff9900', // optional, change the color of the selected tab icon and text (only selected)
+    tabBarButtonColor: '#ffff00', // optional, change the color of the tab icons and text (also unselected). On Android, add this to appStyle
+    tabBarSelectedButtonColor: '#ff9900', // optional, change the color of the selected tab icon and text (only selected). On Android, add this to appStyle
     tabBarBackgroundColor: '#551A8B', // optional, change the background color of the tab bar
-    initialTabIndex: 1, // optional, the default selected bottom tab. Default: 0
+    initialTabIndex: 1, // optional, the default selected bottom tab. Default: 0. On Android, add this to appStyle
   },
   appStyle: {
     orientation: 'portrait', // Sets a specific orientation to the entire app. Default: 'auto'. Supported values: 'auto', 'landscape', 'portrait'