Add selinux denial test to Microdroid test

MicrodroidBoots will also check if there are any SELinux denials while
running the test payload.

Bug: 193118220
Test: atest MicrodroidHostTestCases
Change-Id: I9d55b974466b5b652ce39ea0bc84e1a1ab213b30
diff --git a/tests/hostside/java/android/virt/test/MicrodroidTestCase.java b/tests/hostside/java/android/virt/test/MicrodroidTestCase.java
index 8881c51..aa7c9ab 100644
--- a/tests/hostside/java/android/virt/test/MicrodroidTestCase.java
+++ b/tests/hostside/java/android/virt/test/MicrodroidTestCase.java
@@ -73,6 +73,9 @@
         tryRunOnMicrodroid("watch -e \"getprop debug.microdroid.test.keystore | grep '^$'\"");
         assertThat(runOnMicrodroid("getprop", "debug.microdroid.test.keystore"), is("PASS"));
 
+        // Check that no denials have happened so far
+        assertThat(runOnMicrodroid("logcat -d -e 'avc:[[:space:]]{1,2}denied'"), is(""));
+
         shutdownMicrodroid(getDevice(), cid);
     }