Fix VtsKernelNetTest#VtsKernelNetTest#testKernelNetworking

Bug: 140366925
Change-Id: I2fd94487db3412669ab8bb938010b00cbb54766d
Merged-In: I2fd94487db3412669ab8bb938010b00cbb54766d
(cherry picked from commit d8385e2e7f732a73e9fe9130d3a974d1254681d1)
diff --git a/net/test/srcaddr_selection_test.py b/net/test/srcaddr_selection_test.py
index adbcc54..45a8140 100755
--- a/net/test/srcaddr_selection_test.py
+++ b/net/test/srcaddr_selection_test.py
@@ -287,6 +287,7 @@
                    scapy.ICMPv6ND_NA(tgt=self.test_ip, R=0, S=0, O=1) /
                    scapy.ICMPv6NDOptDstLLAddr(lladdr=conflict_macaddr))
     self.ReceiveEtherPacketOn(self.test_netid, dad_defense)
+    self.WaitForDad(self.test_lladdr)
 
     # The address should have failed DAD, and therefore no longer be usable.
     self.assertAddressNotUsable(self.test_ip, self.test_netid)