Don't run run-test-719 in no-preload config

We need prebuild configs in order to generate a .dm file.

Bug: 122968669
Test: test/testrunner/testrunner.py -t 719 -b --no-prebuild
Change-Id: Icaf402fb8302f4c82a28855d40392552847f1e24
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 8de9574..a1a038a 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -1185,7 +1185,7 @@
     },
     {
         "tests": ["719-dm-verify-redefinition"],
-        "variant": "jvm | speed-profile | interp-ac | target",
+        "variant": "jvm | speed-profile | interp-ac | target | no-prebuild",
         "description": ["Doesn't run on RI because of boot class redefintion.",
                         "Doesn't work with profiles because the run-test is not setup to",
                         "support both. It also needs full verification, so no interp-ac.",