Reorder clatStart() to setup 464xlat sockets before tun interface

Modified the execution sequence within ClatCoordinator.clatStart() to
configure the local 464xlat read/write sockets before configuring and
bringing up the tun interface. This ensures that upon receiving an
RTM_NEWLINK message for the tun interface up event, the anycast address
is already configured on the physical interface.

Test: TH, manual test on physical device
Change-Id: I558cd370456091b8a61e1137a53305527fb651fd
2 files changed