Fix build

library/core/src/main/java/com/google/android/exoplayer2/mediacodec/MediaCodecRenderer.java

@@ -23,6 +23,7 @@ import android.media.MediaCrypto;
 import android.media.MediaFormat;
 import android.os.Looper;
 import android.os.SystemClock;
+import android.support.annotation.IntDef;
 import android.support.annotation.Nullable;
 import android.util.Log;
 import com.google.android.exoplayer2.BaseRenderer;
@@ -43,6 +44,9 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.NalUnitUtil;
 import com.google.android.exoplayer2.util.TraceUtil;
 import com.google.android.exoplayer2.util.Util;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.List;