Modifies the `ChunkSource.getNextChunk(long, long, List, ChunkHolder)` method in the `ChunkSource` interface to `ChunkSource.getNextChunk(LoadingInfo, long, List, ChunkHolder)`.
LoadingInfo contains additional parameters, including `playbackRate` and `lastRebufferRealtimeMs` in addition to the existing `playbackPositionUs`. The additional parameters will allow us to pass these information to Common Media Client Data (CMCD) logging.
PiperOrigin-RevId: 555148768