Revert "Disable test 426 on redefinition configurations."

This reverts commit 68a2386989a081b5937897ed7fb82338418d53be.

Reason for revert: Relanding R8 4.0.12-dev after test fixup

Bug: 236940335
Change-Id: I8acc186c4438b3bc2062706a8ec875daac886cfa
diff --git a/test/knownfailures.json b/test/knownfailures.json
index e70bb49..8983d04 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -414,12 +414,6 @@
         "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"