Carrierprivileges: Addressing API council suggestions.

- hasCarrierPrivileges - renamed to getCarrierPrivilegeStatus
- setLine1NumberForDisplay should not be usable by apps that have MODIFY_PHONE_STATE
- setVoiceMailNumber should not be usable by apps that have MODIFY_PHONE_STATE
- setOperatorBrandOverride should not be usable by apps that have MODIFY_PHONE_STATE

Not addressed:
- setGlobalPreferredNetworkType() should not be usable by apps that have MODIFY_PHONE_STATE

The underlying call is needed by system apps (OMADM) too.

Bug: 18356155
Change-Id: Idc6468a0bd0b0c52b9de1d8446f98c90ac0b3238