Remove unnecessary throws clause

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=156061458

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

@@ -237,7 +237,7 @@ public abstract class MediaCodecRenderer extends BaseRenderer {
   }
   }
 
 
   @Override
   @Override
-  public final int supportsMixedMimeTypeAdaptation() throws ExoPlaybackException {
+  public final int supportsMixedMimeTypeAdaptation() {
     return ADAPTIVE_NOT_SEAMLESS;
     return ADAPTIVE_NOT_SEAMLESS;
   }
   }