Ignore failures on O devices in JDWP tests.

These tests fail with the following exception when run with an
unbundled ART (built from AOSP) on devices running Android O (MR1):

  java.net.SocketTimeoutException: Poll timed out

This is a workaround to stop bot spam while we investigate the root of
the issue.

Test: art/tools/run-jdwp-tests.sh --mode=device
Bug: 74725685
Change-Id: I9edbe1d5ec57fe7b9ecf2d5894fdff6639f30bd6