Fix misleading method names.

Issue: #2414

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=147325759

extensions/opus/src/main/java/com/google/android/exoplayer2/ext/opus/OpusDecoder.java

@@ -213,7 +213,7 @@ import java.util.List;
       SimpleOutputBuffer outputBuffer, int sampleRate);
   private native int opusSecureDecode(long decoder, long timeUs, ByteBuffer inputBuffer,
       int inputSize, SimpleOutputBuffer outputBuffer, int sampleRate,
-      ExoMediaCrypto wvCrypto, int inputMode, byte[] key, byte[] iv,
+      ExoMediaCrypto mediaCrypto, int inputMode, byte[] key, byte[] iv,
       int numSubSamples, int[] numBytesOfClearData, int[] numBytesOfEncryptedData);
   private native void opusClose(long decoder);
   private native void opusReset(long decoder);

extensions/vp9/src/main/java/com/google/android/exoplayer2/ext/vp9/VpxDecoder.java

@@ -141,7 +141,7 @@ import java.nio.ByteBuffer;
   private native long vpxClose(long context);
   private native long vpxDecode(long context, ByteBuffer encoded, int length);
   private native long vpxSecureDecode(long context, ByteBuffer encoded, int length,
-      ExoMediaCrypto wvCrypto, int inputMode, byte[] key, byte[] iv,
+      ExoMediaCrypto mediaCrypto, int inputMode, byte[] key, byte[] iv,
       int numSubSamples, int[] numBytesOfClearData, int[] numBytesOfEncryptedData);
   private native int vpxGetFrame(long context, VpxOutputBuffer outputBuffer);
   private native int vpxGetErrorCode(long context);