Disable runtime app image tests with debuggable.

We don't generate a runtime app image in debuggable mode.

Test: test.py
Change-Id: I5d38b2d0cdf0956592ee0446f517360fd6f82d78
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 550b863..69f9c27 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -1559,5 +1559,10 @@
         "env_vars": {"ART_TEST_DEBUG_GC": "true"},
         "bug": "b/264844668",
         "description": ["Test timing out on debug gc."]
+    },
+    {
+        "tests": ["845-data-image", "846-multidex-data-image"],
+        "variant": "debuggable",
+        "description": ["Runtime app images are not supported with debuggable."]
     }
 ]