Handle null byte array in contacts cache.

http://b/3438334
Change-Id: Id391bcd4564ac10dc4970609eb9382c7500a3778
diff --git a/src/com/android/contacts/ContactPhotoManager.java b/src/com/android/contacts/ContactPhotoManager.java
index 7f1387d..914b697 100644
--- a/src/com/android/contacts/ContactPhotoManager.java
+++ b/src/com/android/contacts/ContactPhotoManager.java
@@ -210,7 +210,7 @@
         int maxBytes = resources.getInteger(R.integer.config_photo_cache_max_bytes);
         mBitmapHolderCache = new LruCache<Object, BitmapHolder>(maxBytes) {
             @Override protected int sizeOf(Object key, BitmapHolder value) {
-                return value.bytes.length;
+                return value.bytes != null ? value.bytes.length : 0;
             }
         };
         mBitmapHolderCacheRedZoneBytes = (int) (maxBytes * 0.75);