This change was originally made in 379cb3ba54.
It was then accidentally lost in when `Cea608Parser` was merged back
into `Cea608Decoder` in 25498b151b.
This was spotted when re-doing a similar lost change to `Cea708Decoder`,
reported in https://github.com/androidx/media/pull/1315.
See reasoning on e2847b3b80
about why this is the only 'lost' CEA-608 change.
PiperOrigin-RevId: 635803536