Add drawUnderTopBar style param

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

     private void addContentView() {
         contentView = new ContentView(getContext(), screenParams, this);
         RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(MATCH_PARENT, MATCH_PARENT);
-        params.addRule(RelativeLayout.BELOW, topBar.getId());
+        if (!screenParams.styleParams.drawUnderTopBar) {
+            params.addRule(RelativeLayout.BELOW, topBar.getId());
+        }
         addView(contentView, params);
         contentView.init();
     }

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

     public boolean topTabsHidden;
     public boolean bottomTabsHidden;
     public boolean bottomTabsHiddenOnScroll;
+    public boolean drawUnderTopBar;
 }

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

         result.topTabsHidden = params.getBoolean("topTabsHidden");
         result.bottomTabsHidden = params.getBoolean("bottomTabsHidden");
         result.bottomTabsHiddenOnScroll = params.getBoolean("bottomTabsHiddenOnScroll");
+        result.drawUnderTopBar = params.getBoolean("drawUnderTopBar", false);
         return result;
     }
 }

src/deprecated/platformSpecificDeprecated.android.js

     backButtonHidden: navigatorStyle.backButtonHidden,
     topTabsHidden: navigatorStyle.topTabsHidden,
     bottomTabsHidden: navigatorStyle.tabBarHidden,
-    bottomTabsHiddenOnScroll: navigatorStyle.bottomTabsHiddenOnScroll
+    bottomTabsHiddenOnScroll: navigatorStyle.bottomTabsHiddenOnScroll,
+    drawUnderTopBar: navigatorStyle.drawUnderNavBar
   };
 
   return _.omit(screen, ['navigatorStyle']);