Maybe fix issue #2568615: System server crashed in SyncStorageEngine

Ack, we were acquiring the wrong lock at some points when
accessing the data structure!

Change-Id: I8bbc8e1ffa2e3e8a94bf7625e3d7f020c458eea2

core/java/android/content/SyncStorageEngine.java

@@ -330,11 +330,11 @@ public class SyncStorageEngine extends Handler {
 
     @Override public void handleMessage(Message msg) {
         if (msg.what == MSG_WRITE_STATUS) {
-            synchronized (mAccounts) {
+            synchronized (mAuthorities) {
                 writeStatusLocked();
             }
         } else if (msg.what == MSG_WRITE_STATISTICS) {
-            synchronized (mAccounts) {
+            synchronized (mAuthorities) {
                 writeStatisticsLocked();
             }
         }