Save country code information in InputDevice

Country code information is passed by a HID device over sysfs.
We can read that information and save it in InputDevice which
will be later used for auto-detecting Layout for PK.
More information in DD: go/pk_auto_layout_detection

Test: atest InputDeviceTest
Bug: 242715614
Change-Id: I97bde1f2338ad601a7e2636600038e6ca124e3ff