Fix TetheringTest when run on B

Tethering will ignore interfaceStatusChanged for enabled interfaces
starting in B, instead only creating the IpServer when the link layer
event comes. Fix the assertions around interfaceStatusChanged for B.

Bug: 393978354
Test: atest TetheringTest
Change-Id: I74d0843785c5d9353e59b73d6d7b30d6d07ac0e0
1 file changed