Skip scheduled HLS playlists refreshes if no longer primary or active

When a playlist refresh is scheduled with a delay, the load should only proceed if the playlist is still the primary media playlist or is currently active for playback. This prevents unnecessary reloads of playlists that are no longer required after track switch.

Issue: androidx/media#3254

#cherrypick

PiperOrigin-RevId: 941601359
(cherry picked from commit 520a02447c30dd5a6d0ab653ac3a36bd570c57d8)