Fix art-buildbot host-x86-gcstress-debug

Disable the following tests on the host-x86-gcstress-debug to unblock
art-buildbot. Tests are failing due to unknown reason with a
"java.io.IOException: Stream closed" which is tracked in a separate
bug.

Bug: 235566533
Bug: 208639267
Test: art/tools/run-libcore-tests.sh --mode=host --variant=X32 \
      --gcstress --debug
Change-Id: I0882a2c067ae0d4ff9a382f49cfe464b31c45fee
2 files changed