Add mainline skipping to CVE-20201-0311

Also set the ASB to 2021-01

Bug: 170240631
Test: sts-tradefed run sts-engbuild-no-spl-lock -m CtsSecurityTestCases -t android.security.cts.StagefrightTest#testStagefright_bug170240631
Change-Id: Ieb25e98a5b3f3f90157e032f7fd1aa680749d8e8
diff --git a/tests/tests/security/src/android/security/cts/StagefrightTest.java b/tests/tests/security/src/android/security/cts/StagefrightTest.java
index 9592d20..7146bdf 100644
--- a/tests/tests/security/src/android/security/cts/StagefrightTest.java
+++ b/tests/tests/security/src/android/security/cts/StagefrightTest.java
@@ -1377,8 +1377,11 @@
     }
 
     @Test
-    @SecurityTest(minPatchLevel = "Unknown")
+    @SecurityTest(minPatchLevel = "2021-01")
     public void testStagefright_bug170240631() throws Exception {
+        assumeFalse(ModuleDetector.moduleIsPlayManaged(
+            getInstrumentation().getContext().getPackageManager(),
+            MainlineModule.MEDIA));
         doStagefrightTest(R.raw.bug170240631_ts);
     }