Do not reference test 648-many-direct-methods in test/knownfailures.json.

This test has been removed from the ART test suite.

Test: m test-art-host
Change-Id: I100b393ec278cf6d0a01d98af7966480fc8e3c1b
diff --git a/test/knownfailures.json b/test/knownfailures.json
index c7ad5bf..f7fb357 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -667,12 +667,6 @@
         "bug": "b/37636792"
     },
     {
-        "tests": "648-many-direct-methods",
-        "variant": "optimizing",
-        "description": "Test disabled with AOT because of dex2oatd timeouts.",
-        "bug": "b/33650497"
-    },
-    {
         "tests": [
             "536-checker-needs-access-check",
             "537-checker-inline-and-unverified",