apn: Ting: Adding missing flag to list of types

Adding "default" to the type list, will allow to connect to mobile internet via LTE again.
According to the user, even if enforcing LTE here, it won't work unless adding "default".

I couldn't find any official resources, just that this APN seems to relate to CDMA and other people fixed the issue by adding the APN manually:
https://help.ting.com/hc/en-us/community/posts/206433277/comments/216019607

Therefore trusting the reporter in the ticket below that default is enough:
https://gitlab.com/LineageOS/issues/android/-/issues/2819

Change-Id: I931f5355af74e197020032a1581dd11abf84f10c