Render first tab first

Until now tabs were added to screen in reverse order, meaning the last tab was attached to hierarchy first and the first tab was attached last.
This caused the first tab, which usually should appear first, to be rendered last as the root view’s startReactApplication was called last.
This commit changes render order so that the first tab is rendered first. Some apps will probably see an improvement in time to interaction as a result.

lib/android/app/src/main/java/com/reactnativenavigation/viewcontrollers/bottomtabs/BottomTabsController.java

 	}
 
     private void attachTabs(RelativeLayout root) {
-        for (int i = (tabs.size() - 1); i >= 0; i--) {
+        for (int i = 0; i < tabs.size(); i++) {
             ViewGroup tab = tabs.get(i).getView();
             tab.setLayoutParams(new RelativeLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT));
             Options options = resolveCurrentOptions();

lib/android/app/src/test/java/com/reactnativenavigation/viewcontrollers/BottomTabsControllerTest.java

     public void setTabs_firstChildIsVisibleOtherAreGone() {
         uut.onViewAppeared();
         for (int i = 0; i < uut.getChildControllers().size(); i++) {
-            assertThat(uut.getView().getChildAt(i).getVisibility()).isEqualTo(i == 0 ? View.VISIBLE : View.INVISIBLE);
+            assertThat(uut.getView().getChildAt(i + 1)).isEqualTo(tabs.get(i).getView());
+            assertThat(uut.getView().getChildAt(i + 1).getVisibility()).isEqualTo(i == 0 ? View.VISIBLE : View.INVISIBLE);
         }
     }