`TrackSelectorResult.rendererConfigurations` can contain null elements:
> A null entry indicates the corresponding renderer should be disabled.
This wasn't caught by the nullness checker because `ExoPlayerImpl` is
currently excluded from analysis.
#minor-release
Issue: google/ExoPlayer#10977
PiperOrigin-RevId: 508619169
(cherry picked from commit 5e3cd7a3)
