add back removed tests

library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractorTest.java

@@ -64,6 +64,12 @@ public final class MatroskaExtractorTest {
   }
 
   @Test
+  public void webmSubsampleEncryptionWithAltrefFrames() throws Exception {
+    ExtractorAsserts.assertBehavior(
+        MatroskaExtractor::new, "mkv/subsample_encrypted_altref.webm", simulationConfig);
+  }
+
+  @Test
   public void mkvSampleWithProfile5DolbyVision() throws Exception {
     ExtractorAsserts.assertBehavior(
         MatroskaExtractor::new, "mkv/dvhe_05_05.mkv", simulationConfig);
@@ -73,5 +79,5 @@ public final class MatroskaExtractorTest {
   public void mkvSampleWithProfile8DolbyVision() throws Exception {
     ExtractorAsserts.assertBehavior(
         MatroskaExtractor::new, "mkv/hev1_08_05.mkv", simulationConfig);
-  }
+  }g
 }