Disable libcore.libcore.io.FdsanTest#testSocket on target.

The test is now timing out on heap-poisoning target builds. Disable it
to avoid the bot spam while we investigate the issue.

Test: Rely on the ART Buildbot's heap-poisoning target builders.
Bug: 116446372
Change-Id: I412b1c32a3477501a131b4e07045ee8ccbc61fba
1 file changed