CarrierConfig: add the wifi configs for Carrier-Wifi Application.

The new configs for wifi will be used in Carrier Wi-Fi Application to
connect the wifi networks defined by a carrier.

Bug: 129964730
Test: unit test
Change-Id: I4d02a19d25626d7331f139e9e85062b05720ac51
Signed-off-by: Ecco Park <eccopark@google.com>