Remove unused classes from session module

Remove PlayerNotificationManager and DefaultMediaDescriptionAdapter
which are unused in session. The functionality is covered by the
MediaNotification.Provider.

PiperOrigin-RevId: 446687875

libraries/session/src/main/java/androidx/media3/session/DefaultMediaDescriptionAdapter.java

-/*
- * Copyright 2021 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package androidx.media3.session;
-
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.text.TextUtils;
-import androidx.annotation.Nullable;
-import androidx.media3.common.Player;
-import androidx.media3.common.util.UnstableApi;
-import androidx.media3.session.PlayerNotificationManager.BitmapCallback;
-import androidx.media3.session.PlayerNotificationManager.MediaDescriptionAdapter;
-
-/**
- * Default implementation of {@link MediaDescriptionAdapter}.
- *
- * <p>Uses values from the {@link Player#getMediaMetadata() player mediaMetadata} to populate the
- * notification.
- */
-@UnstableApi
-public final class DefaultMediaDescriptionAdapter implements MediaDescriptionAdapter {
-
-  /** Creates a default {@link MediaDescriptionAdapter}. */
-  public DefaultMediaDescriptionAdapter() {}
-
-  @Override
-  public CharSequence getCurrentContentTitle(MediaSession session) {
-    Player player = session.getPlayer();
-    @Nullable CharSequence displayTitle = player.getMediaMetadata().displayTitle;
-    if (!TextUtils.isEmpty(displayTitle)) {
-      return displayTitle;
-    }
-
-    @Nullable CharSequence title = player.getMediaMetadata().title;
-    return title != null ? title : "";
-  }
-
-  @Nullable
-  @Override
-  public CharSequence getCurrentContentText(MediaSession session) {
-    Player player = session.getPlayer();
-    @Nullable CharSequence artist = player.getMediaMetadata().artist;
-    if (!TextUtils.isEmpty(artist)) {
-      return artist;
-    }
-
-    return player.getMediaMetadata().albumArtist;
-  }
-
-  @Nullable
-  @Override
-  public Bitmap getCurrentLargeIcon(MediaSession session, BitmapCallback callback) {
-    Player player = session.getPlayer();
-    @Nullable byte[] data = player.getMediaMetadata().artworkData;
-    if (data == null) {
-      return null;
-    }
-    return BitmapFactory.decodeByteArray(data, /* offset= */ 0, data.length);
-  }
-}