[RFCLAT#3] Move the tun interface setup from clatd to netd am: 5dafb0e92c am: a518daebcc

Original change: https://android-review.googlesource.com/c/platform/external/android-clat/+/1903035

Change-Id: Iafcbc3051b314e78f20cf6c77022a00e9064daa2