Fixed crash in "calendar to sync" when there are accounts with identical email addresses

If there are multiple accounts with the same account_name,
"Calendar to sync" would crash because we are closing the same cursor multiple times.
There's a hashmap which uses the account_email as the key and ignores the account_type.

Bug: 6540605
Change-Id: I0c39bece20b8a56d2d4b9ca002efe6342287484a