Temporary fix for the issue in Contacts that makes the wrong photo to be shown.

The issue appears to have something to do with extensive
concurrency going on there. For now I am just shrinking
the thread pool to one thread and that seems to be addressing
the problem.  Next step will be to redesign the photo loading.

Bug: 2441230
Change-Id: I829bf11c4dd9699719fe556223669d477ebdbfc1
diff --git a/src/com/android/contacts/ContactsListActivity.java b/src/com/android/contacts/ContactsListActivity.java
index 29f059d..235cff9 100644
--- a/src/com/android/contacts/ContactsListActivity.java
+++ b/src/com/android/contacts/ContactsListActivity.java
@@ -3330,9 +3330,9 @@
             synchronized (ContactsListActivity.this) {
                 // can't sync on sImageFetchThreadPool.
                 if (sImageFetchThreadPool == null) {
-                    // Don't use more than 3 threads at a time to update. The thread pool will be
-                    // shared by all contact items.
-                    sImageFetchThreadPool = Executors.newFixedThreadPool(3);
+                    // TODO: redesign this so that all DB interaction happens
+                    // on a single background thread and loads photos in bulk.
+                    sImageFetchThreadPool = Executors.newFixedThreadPool(1);
                 }
                 sImageFetchThreadPool.execute(mImageFetcher);
             }