The `DefaultPreloadManager.Builder` is able to build the `DefaultPreloadManager` and `ExoPlayer` instances with the consistently shared configurations. Apps can:
* Simply setup the `DefaultPreloadManager` and `ExoPlayer` with all default configurations via `build()` and `buildExoPlayer()`;
* Or customize the shared configurations by the setters on `DefaultPreloadManager.Builder` and setup via `build()` and `buildExoPlayer()`;
* Or customize the player-only configurations for `ExoPlayer` via `buildExoPlayer(ExoPlayer.Builder)`.
PiperOrigin-RevId: 684852808