Using the wrong selection for Exchange accounts

Exchange accounts support nested folders, so, we need to use the selection
that excludes any mailboxes with IDs greater than 0. Otherwise, we see all
mailboxes on the account.

Change-Id: If8c2085458176e8bd87013e3b598bd7740c652b2

src/com/android/email/activity/MailboxFragmentAdapter.java

@@ -172,7 +172,7 @@ import android.widget.TextView;
         // STOPSHIP remove when legacy protocols support folders; parent key must always be set
         MailboxFragmentLoader(Context context, long accountId) {
             super(context, EmailContent.Mailbox.CONTENT_URI,
-                    MailboxesAdapter.PROJECTION, MAILBOX_SELECTION,
+                    MailboxesAdapter.PROJECTION, MAILBOX_SELECTION_NO_PARENT,
                     new String[] { Long.toString(accountId) },
                     MAILBOX_ORDER_BY);
             mContext = context;