Send bottomTabSelectedEvent before switching tab

fixes #2711

android/app/src/main/java/com/reactnativenavigation/layouts/BottomTabsLayout.java

         }
 
         final int unselectedTabIndex = currentStackIndex;
-        switchTab(position, NavigationType.BottomTabSelected);
         sendTabSelectedEventToJs(position, unselectedTabIndex);
+        switchTab(position, NavigationType.BottomTabSelected);
         return true;
     }