[Android] Fix list frozen in wrong condition.

* issue: #2250

Author: huanglei.hl

android/sdk/src/main/java/com/taobao/weex/ui/component/list/BasicListComponent.java

@@ -734,16 +734,16 @@ public void addChild(WXComponent child, int index) {
       }
       if (isKeepScrollPosition) {
         if(view.getInnerView().getLayoutManager() instanceof  LinearLayoutManager){
-          if(!view.getInnerView().isLayoutFrozen()){ //frozen, prevent layout when scroll
-            view.getInnerView().setLayoutFrozen(true);
-          }
           if(keepPositionCell == null){
             int last=((LinearLayoutManager)view.getInnerView().getLayoutManager()).findLastCompletelyVisibleItemPosition();
             ListBaseViewHolder holder = (ListBaseViewHolder) view.getInnerView().findViewHolderForAdapterPosition(last);
             if(holder != null){
               keepPositionCell = holder.getComponent();
             }
             if(keepPositionCell != null) {
+              if(!view.getInnerView().isLayoutFrozen()){ //frozen, prevent layout when scroll
+                view.getInnerView().setLayoutFrozen(true);
+              }
               if(keepPositionCellRunnable != null){
                 view.removeCallbacks(keepPositionCellRunnable);
               }