* Struct.java is removed from net-utils-device-common-bpf and
net-utils-device-common-struct's source list
* Created a lib net-utils-device-common-struct-base for Struct.java
* Updated libs that require Struct.java to include
net-utils-device-common-struct-base.
* Replaced net-utils-multicast-forwarding-structs with
net-utils-device-common-struct in service-connectivity
Bug: 323503345
Test: build tethering module.
Change-Id: I3f60715c3d8043b7569db7612dee9d4fa1ccba59
3aa62e6773