[Provider Model] Carrier configurations to allow CWF configurations

Add a Carrier Configuration which indicates that the carrier will
configure Carrier Wi-Fi offload networks.

Bug: 181277417
Test: atest com.android.server.wifi
Test: atest android.net.wifi
Change-Id: I7308ab465a5de34f103e20c4f7f974114d5dbb1f
2 files changed