Blacklist test failing on debuggable.

Bug: 149168708
Test: 596-app-images
Change-Id: Ic0c790c6707df0c9784e9436abc2b94bd2db6c5b
diff --git a/test/knownfailures.json b/test/knownfailures.json
index d4d279c..630c58a 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -308,6 +308,12 @@
         "variant": "interp-ac"
     },
     {
+        "tests": "596-app-images",
+        "description": "Fails on debuggable",
+        "bug" : "b/149168708",
+        "variant": "debuggable"
+    },
+    {
         "tests": "597-app-images-same-classloader",
         "description": "not generated when using the access check configuration",
         "variant": "interp-ac"