Use identical media item for constructor if possible

If no deprecated methods on the factory is called, the media item instance that is passed to the createMediaSource method must be passed down to the constructor of the media source.

PiperOrigin-RevId: 314193865

library/core/src/main/java/com/google/android/exoplayer2/source/ProgressiveMediaSource.java

@@ -180,15 +180,18 @@ public final class ProgressiveMediaSource extends BaseMediaSource
     @Override
     public ProgressiveMediaSource createMediaSource(MediaItem mediaItem) {
       checkNotNull(mediaItem.playbackProperties);
-      MediaItem.Builder builder = mediaItem.buildUpon();
-      if (mediaItem.playbackProperties.tag == null) {
-        builder.setTag(tag);
-      }
-      if (mediaItem.playbackProperties.customCacheKey == null) {
-        builder.setCustomCacheKey(customCacheKey);
+      boolean needsTag = mediaItem.playbackProperties.tag == null && tag != null;
+      boolean needsCustomCacheKey =
+          mediaItem.playbackProperties.customCacheKey == null && customCacheKey != null;
+      if (needsTag && needsCustomCacheKey) {
+        mediaItem = mediaItem.buildUpon().setTag(tag).setCustomCacheKey(customCacheKey).build();
+      } else if (needsTag) {
+        mediaItem = mediaItem.buildUpon().setTag(tag).build();
+      } else if (needsCustomCacheKey) {
+        mediaItem = mediaItem.buildUpon().setCustomCacheKey(customCacheKey).build();
       }
       return new ProgressiveMediaSource(
-          builder.build(),
+          mediaItem,
           dataSourceFactory,
           extractorsFactory,
           drmSessionManager,