Camera2: Mark more tests as known failures

Also update the bug for the previously-added known failure.

Bug: 17504297
Change-Id: Ibb31ac8083f8821ea4c9b1599ef9cedbe3f3d6f4
diff --git a/tests/expectations/knownfailures.txt b/tests/expectations/knownfailures.txt
index 131b264..706a663 100644
--- a/tests/expectations/knownfailures.txt
+++ b/tests/expectations/knownfailures.txt
@@ -60,6 +60,14 @@
   names: [
     "android.hardware.camera2.cts.RobustnessTest#testMandatoryOutputCombinations"
   ],
-  bug: 16899526
+  bug: 17511208
+},
+{
+  description: "these tests require a good test scene, so they fail if run in random conditions",
+  names: [
+    "android.hardware.camera2.cts.AllocationTest#testBlackWhite",
+    "android.hardware.camera2.cts.AllocationTest#testParamSensitivity"
+  ],
+  bug: 17530117
 }
 ]