Show surfaceId when logging IntBufferBatchMountItem

Summary:
Adds surface id for string logs of the IntBufferBatchMountItem to help debug updates with multiple surfaces.

Changelog: [Internal]

Reviewed By: JoshuaGross

Differential Revision: D27884232

fbshipit-source-id: c5ec65585830f7aa5b902603bcd1e91b61cfe4c1

ReactAndroid/src/main/java/com/facebook/react/fabric/mounting/mountitems/IntBufferBatchMountItem.java

@@ -193,7 +193,7 @@ public class IntBufferBatchMountItem implements MountItem {
   public String toString() {
     try {
       StringBuilder s = new StringBuilder();
-      s.append("IntBufferBatchMountItem:");
+      s.append(String.format("IntBufferBatchMountItem [surface:%d]:\n", mSurfaceId));
       int i = 0, j = 0;
       while (i < mIntBufferLen) {
         int rawType = mIntBuffer[i++];