Should not try IMS or EMERGENCY APN for initial-attach.

This helps to avoid the problem where the auto-generated
IMS or EMERGENCY APN being used for initial-attach due to
racing conditions.

Some carriers may require IMS APN for initial-attach. That case,
the IA type should have been added to the APN explicitly to prevent
the DEFAULT APN from being used.

Bug: 186120396
Change-Id: Ic5e449e514a996f90b815e56fe136ac1f453496e
Test: manual