Draw all views above BottomTabs

Since we don't fully support hideOnScroll property yet, draw all views
above BottomTabs

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

@@ -50,7 +50,9 @@ public class BottomTabsLayout extends RelativeLayout implements Layout, AHBottom
         ScreenStack newStack = new ScreenStack(activity, params.tabParams.get(position));
         screenStacks[position] = newStack;
         newStack.setVisibility(INVISIBLE);
-        addView(newStack, 0, new LayoutParams(MATCH_PARENT, MATCH_PARENT));
+        LayoutParams lp = new LayoutParams(MATCH_PARENT, MATCH_PARENT);
+        lp.addRule(ABOVE, bottomTabs.getId());
+        addView(newStack, 0, lp);
     }
 
     private void createBottomTabs() {

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

@@ -7,6 +7,7 @@ import com.aurelhubert.ahbottomnavigation.AHBottomNavigation;
 import com.aurelhubert.ahbottomnavigation.AHBottomNavigationItem;
 import com.reactnativenavigation.params.ScreenParams;
 import com.reactnativenavigation.params.StyleParams;
+import com.reactnativenavigation.utils.ViewUtils;
 
 import java.util.List;
 
@@ -14,6 +15,7 @@ public class BottomTabs extends AHBottomNavigation {
     public BottomTabs(Context context) {
         super(context);
         setForceTint(true);
+        setId(ViewUtils.generateViewId());
     }
 
     public void addTabs(List<ScreenParams> params, OnTabSelectedListener onTabSelectedListener) {