Revert^2 "Disable test 426 on redefinition configurations."

This reverts commit 672bab4bcf6c6439e2d3f4c27a3c497171c9b2af.

Reason for revert: The revert of R8 4.0.12-dev causes this again to fail.

Change-Id: Ice476348863af59d481a1f24501627a4bbdaaa4a
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 8983d04..e70bb49 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -414,6 +414,12 @@
         "variant": "jvmti-stress | redefine-stress"
     },
     {
+        "tests": [ "426-monitor"],
+        "description": ["Hitting an issue with slicer."],
+        "bug": "http://b/235319568",
+        "variant": "jvmti-stress | redefine-stress"
+    },
+    {
         "test_patterns": ["[0-9]*-checker-.*"],
         "description": ["Checker tests are not compatible with jvmti."],
         "variant": "jvmti-stress | redefine-stress | trace-stress | field-stress | step-stress"