Fix broken Javadoc

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=213951977

extensions/mediasession/src/main/java/com/google/android/exoplayer2/ext/mediasession/MediaSessionConnector.java

@@ -401,7 +401,7 @@ public final class MediaSessionConnector {
    * <p>The order in which any {@link CustomActionProvider}s are passed determines the order of the
    * actions published with the playback state of the session.
    *
-   * @param player The player to be connected to the {@code MediaSession}, or {@link null} to
+   * @param player The player to be connected to the {@code MediaSession}, or {@code null} to
    *     disconnect the current player.
    * @param playbackPreparer An optional {@link PlaybackPreparer} for preparing the player.
    * @param customActionProviders Optional {@link CustomActionProvider}s to publish and handle