Missing fab in pushed screen (#613)

* Fix navigator buttons immutability issue

* Show fab in pushed screen

android/app/src/main/java/com/reactnativenavigation/events/ScreenChangedEvent.java

 
 import com.reactnativenavigation.params.BaseScreenParams;
 import com.reactnativenavigation.params.FabParams;
-import com.reactnativenavigation.params.PageParams;
 
 public class ScreenChangedEvent implements Event {
     public static final String TYPE = "ScreenChangedEvent";
     public FabParams fabParams;
 
     public ScreenChangedEvent(BaseScreenParams screenParams) {
-        this.fabParams = screenParams.fabParams;
-    }
-
-    public ScreenChangedEvent(PageParams topTabParams) {
-        this.fabParams = topTabParams.fabParams;
+        this.fabParams = screenParams.getFab();
     }
 
     @Override

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

     public boolean hasCollapsingTopBar() {
         return styleParams.collapsingTopBarParams != null;
     }
+
+    public FabParams getFab() {
+        return fabParams;
+    }
 }

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

     public boolean hasTopTabs() {
         return topTabParams != null && !topTabParams.isEmpty();
     }
+
+    public FabParams getFab() {
+        return hasTopTabs() ? topTabParams.get(0).fabParams : null;
+    }
 }

src/deprecated/platformSpecificDeprecated.android.js

 }
 
 function adaptTopTabs(screen, navigatorID) {
+  screen.topTabs = _.cloneDeep(screen.topTabs);
   _.forEach(_.get(screen, 'topTabs'), (tab) => {
     addNavigatorParams(tab);
     if (navigatorID) {
     }
   }
   const fab = getFab(params);
-  console.log('params: ', JSON.stringify(params));
-  console.log('fab: ', JSON.stringify(fab));
   newPlatformSpecific.setScreenButtons(navigator.screenInstanceID, navigatorEventID, params.rightButtons, leftButton, fab);
 }