send out IPv6 DAD packets when starting up clatd for the clat v6 address am: f6ec94ea69 am: 93fc5ff60a

Original change: https://android-review.googlesource.com/c/platform/external/android-clat/+/2153053

Change-Id: Ifbca20848e70ff4ea72c766669e0b2e0d83fb16f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>