Delete old TODO.

This was resolved in https://github.com/google/ExoPlayer/commit/081700f72b2a43e1e0d01a0130cf283c7d59b9bc where the
Video/AudioSamplePipeline call this method before calling
the FallbackListener.

PiperOrigin-RevId: 423284258

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/Codec.java

@@ -157,8 +157,6 @@ public final class Codec {
    * DecoderFactory} or output {@link Format} used by the {@link EncoderFactory} for selecting and
    * configuring the underlying {@link MediaCodec}.
    */
-  // TODO(b/214012830): Use this to check whether the Format passed to the factory and actual
-  // configuration format differ to see whether fallback was applied.
   public Format getConfigurationFormat() {
     return configurationFormat;
   }