Workaround system peculiarity to fix #2134509

* Our AccountManager listener was getting unregistered due to the way
  ApplicationContext caches AccountManager in a static member
* The result was that AccountManager registers its listeners against the
  FIRST context it is instantiated with!  Future calls will all obtain
  this pre-initialized AccountManager.
* In this case, AccountSetupOptions was the first caller (to create the
  AccountManager Account for Exchange)
* The subsequent call to register a listener therefore had its registration
  tied to the context of AccountSetupOptions, and was therefore leaked
  when AccountSetupOptions finished!
* This caused a chain of problems - the leaked receiver, an Exception in
  AccountManager when trying to ping the listener in an expired context,
  and eventually the bug referenced above, which became a P1 issue

Change-Id: I478e28d21ca77419afa8011e4ed8101cdf67ab79

src/com/android/email/activity/setup/AccountSetupOptions.java

@@ -202,7 +202,9 @@ public class AccountSetupOptions extends Activity implements OnClickListener {
                 && mAccount.mHostAuthRecv != null
                 && mAccount.mHostAuthRecv.mProtocol.equals("eas")) {
             boolean alsoSyncContacts = mSyncContactsView.isChecked();
-            ExchangeStore.addSystemAccount(this, mAccount,
+            // NOTE: We must use the Application here, rather than the current context, because
+            // all future references to AccountManager will end up using the context passed in here!
+            ExchangeStore.addSystemAccount(getApplication(), mAccount,
                     alsoSyncContacts, mAccountManagerCallback);
         } else {
             finishOnDone();

src/com/android/exchange/SyncManager.java

@@ -1333,8 +1333,8 @@ public class SyncManager extends Service implements Runnable {
         ContentResolver.addStatusChangeListener(ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS,
                 mSyncStatusObserver);
         mAccountsUpdatedListener = new EasAccountsUpdatedListener();
-        AccountManager.get(this).addOnAccountsUpdatedListener(mAccountsUpdatedListener,
+        AccountManager.get(getApplication())
-                mHandler, true);
+            .addOnAccountsUpdatedListener(mAccountsUpdatedListener, mHandler, true);
 
         mConnectivityReceiver = new ConnectivityReceiver();
         registerReceiver(mConnectivityReceiver,