Disable ART run-test 648-many-direct-methods with "no-image".

This test takes too long with dex2oatd on "no-image" configurations.

Test: m test-art-host
Bug: b/33650497
Change-Id: Ia55bd62a2db97e63b2b2c4316a0495e3c7d6d2a3
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 7c17ed0..8df7466 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -668,7 +668,7 @@
     },
     {
         "tests": "648-many-direct-methods",
-        "variant": "optimizing | speed-profile",
+        "variant": "optimizing | speed-profile | no-image",
         "description": "Test disabled with AOT because of dex2oatd timeouts.",
         "bug": "b/33650497"
     }