Update test expectation for no-image.

no-image acts like no-prebuild in the context of
OatFileAssistant's default compiler filter change.

Test: test.py --no-image
Change-Id: If3c1fea74bc4eb4ea94752d6d69cf72f18934d65
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 41e41d7..f515226 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -715,7 +715,7 @@
     {
         "tests": ["137-cfi", "629-vdex-speed"],
         "description": [ "Tests require speed compilation which is no longer the default for",
-                          "no-prebuild configs."],
-        "variant": "no-prebuild"
+                          "no-prebuild or no-image configs."],
+        "variant": "no-prebuild | no-image"
     }
 ]