Camera2: Mandatory stream configuration combinations test

Also mark this test as a known failure, since currently it
freezes CTS runs on some devices.

Bug: 16899526

Change-Id: I0e7560b9df004d74546a594efc423d8460f28a31
diff --git a/tests/expectations/knownfailures.txt b/tests/expectations/knownfailures.txt
index 0ab6acb..23c7437 100644
--- a/tests/expectations/knownfailures.txt
+++ b/tests/expectations/knownfailures.txt
@@ -54,5 +54,11 @@
     "android.openglperf.cts.GlVboPerfTest#testVboWithVaryingIndexBufferNumbers"
   ],
   bug: 17394321
-}
+},
+{
+  description: "this test deadlocks on some devices, freezing CTS runs, marking known failure until resolved",
+  names: [
+    "android.hardware.camera2.cts.RobustnessTest#testMandatoryOutputCombinations"
+  ],
+  bug: 16899526
 ]