Fix formatting numbers in concat node (software-mansion#720)

It turned out that IOS doesn't take locale into consideration when formatting NSNumber, so
this commit fixes that on android

android/src/main/java/com/swmansion/reanimated/nodes/ConcatNode.java

@@ -1,16 +1,18 @@
 package com.swmansion.reanimated.nodes;
 
 import java.text.NumberFormat;
+import java.util.Locale;
 
 import com.facebook.react.bridge.ReadableMap;
 import com.swmansion.reanimated.NodesManager;
 import com.swmansion.reanimated.Utils;
 
 public class ConcatNode extends Node {
   private final int[] mInputIDs;
-  private final static NumberFormat sFormatter = NumberFormat.getInstance();
+  private final static NumberFormat sFormatter = NumberFormat.getInstance(Locale.ENGLISH);
   static {
     sFormatter.setMinimumFractionDigits(0);
+    sFormatter.setGroupingUsed(false);
   }
 
   public ConcatNode(int nodeID, ReadableMap config, NodesManager nodesManager) {