[Test] Skip MdnsIPv6LinkLocalWithDefaultRoute on Kernel 4.4

The test failed on kernel 4.4 since the kernel does not provide an IPv6
link-local address when an interface is added to a network. The IPv6
link-local address is a prerequisite for this test. Considering 4.4 is
outdated and EOL'ed, skip the test directly.

[Kernel 4.4]
netd    : networkCreatePhysical(10000, 0) <0.58ms>
netd    : networkAddInterface(10000, "testtun10000") <2.79ms>

$ adb shell ifconfig
testtun10000 Link encap:UNSPEC
    UP POINTOPOINT RUNNING  MTU:1500  Metric:1
    ...

-----------------------------------------------------

[Kernel 4.9+]
netd    : networkCreatePhysical(10000, 0) <0.24ms>
netd    : networkAddInterface(10000, "testtun10000") <3.22ms>

$ adb shell ifconfig
testtun10000 Link encap:UNSPEC
    inet6 addr: fe80::c1b1:ba3c:d875:9bc/64 Scope: Link
    UP POINTOPOINT RUNNING  MTU:1500  Metric:1
    ...

Bug: 247693272
Test: atest ResolverMultinetworkTest
Change-Id: I13961d824045a1ebcce7fc513fdbfcd547d341ed