exclude multicast tests in virtual device testing

- due to limitations in test infra setup for virtual devices

Bug: 35922755
Test: cts-tradefed run cts-dev --collect-tests-only \
    --m CtsLibcoreTestCases \
    --compatibility:module-arg \
    CtsLibcoreTestCases:core-expectation:/virtualdeviceknownfailures.txt
    Verify that the generated test result list no longer
    contains the excluded tests.

Merged-In: Id7e01f64f3e776f4e68a9c0a8eb6c6cdb7a619ff
Change-Id: Id7e01f64f3e776f4e68a9c0a8eb6c6cdb7a619ff
(cherry picked from commit 1dcc53ed566f392777af78f9999804cccbff6fd3)
1 file changed