Delete old TODO.

This was resolved in https://github.com/androidx/media/commit/a652c90483259fed121e61013ec2a96402782600 where the
Video/AudioSamplePipeline call this method before calling
the FallbackListener.

PiperOrigin-RevId: 423284258

libraries/transformer/src/main/java/androidx/media3/transformer/Codec.java

@@ -159,8 +159,6 @@ 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;
   }