support parent carrier id

The parent-child relationship can be used to further differentiate a
single carrier by different networks, by prepaid v.s. postpaid
or even by 4G v.s. 3G plan. parent carrier id it's an optional field.
A carrier id with a valid parent_carrier_id is considered fine-grained carrier id,
will not be returned as API getSimCarrierId but will be returned as
new API getSimPreciseCarrierId.

Bug: 110559381
Change-Id: Ica273cbad16b4773edc41b79ff4bf7570de40ec1