Fix measureLayout function for Virtual Nodes

Summary:
This diff fixes a NullPointerException thrown when calling measureLayout function on a virtual node.

changelog: [Android] Fix measureLayout function for VirtualTexts

Reviewed By: JoshuaGross

Differential Revision: D21435030

fbshipit-source-id: aba6d81f333464e49d2d769b111842e7ae8ce769

ReactAndroid/src/main/java/com/facebook/react/uimanager/UIImplementation.java

@@ -805,7 +805,7 @@ public class UIImplementation {
       ReactShadowNode node, ReactShadowNode ancestor, int[] outputBuffer) {
     int offsetX = 0;
     int offsetY = 0;
-    if (node != ancestor) {
+    if (node != ancestor && !node.isVirtual()) {
       offsetX = Math.round(node.getLayoutX());
       offsetY = Math.round(node.getLayoutY());
       ReactShadowNode current = node.getParent();