get group identifier level1 (Gid1)

To recognize MVNO(Mobile Virtual Network Operator), need some filters,
Service Provider Name(SPN), International Mobile Subscriber ID(IMSI),
and Group Identifier Level1(Gid1).
The GID1 elementary files on the SIM are specified in GSM 11.11 (ETS 300 977)

To get Gid1, implement it.

Bug: 8143480
Change-Id: I44f9d622240a73c42ea6418d2d55e1dae23f3b81