Remove wrong documentation.

This is a left-over from the past and is no longer true.

PiperOrigin-RevId: 236089921

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayer.java

@@ -153,18 +153,12 @@ public interface ExoPlayer extends Player {
   /**
    * Prepares the player to play the provided {@link MediaSource}. Equivalent to
    * {@code prepare(mediaSource, true, true)}.
-   * <p>
-   * Note: {@link MediaSource} instances are not designed to be re-used. If you want to prepare a
-   * player more than once with the same piece of media, use a new instance each time.
    */
   void prepare(MediaSource mediaSource);
 
   /**
    * Prepares the player to play the provided {@link MediaSource}, optionally resetting the playback
    * position the default position in the first {@link Timeline.Window}.
-   * <p>
-   * Note: {@link MediaSource} instances are not designed to be re-used. If you want to prepare a
-   * player more than once with the same piece of media, use a new instance each time.
    *
    * @param mediaSource The {@link MediaSource} to play.
    * @param resetPosition Whether the playback position should be reset to the default position in