Fix source code so it compiles on google3

This is a follow up to cr/65191596 which checked for String + array warnings.

Change-Id: Id70eaa32b63b838b03be21d632c7470039b6423f
diff --git a/src/com/android/launcher3/ItemInfo.java b/src/com/android/launcher3/ItemInfo.java
index 3fe4c60..9ac9edf 100644
--- a/src/com/android/launcher3/ItemInfo.java
+++ b/src/com/android/launcher3/ItemInfo.java
@@ -23,6 +23,7 @@
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.util.Arrays;
 
 /**
  * Represents an item in the launcher.
@@ -182,6 +183,6 @@
     public String toString() {
         return "Item(id=" + this.id + " type=" + this.itemType + " container=" + this.container
             + " screen=" + screenId + " cellX=" + cellX + " cellY=" + cellY + " spanX=" + spanX
-            + " spanY=" + spanY + " dropPos=" + dropPos + ")";
+            + " spanY=" + spanY + " dropPos=" + Arrays.toString(dropPos) + ")";
     }
 }