Merge "Implement registerSystemDefaultNetworkCallback replacement in api30" am: 7c2f81d7e1 am: 2d02bdb70d am: a0888f5e74

Original change: https://android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/1699885

Change-Id: I8f5aeceec85028dd557e756c7ca7a8b5005ea19a