CEA-608 Improper screen size used to calculate HTML lines

[ZygmuntMalek]

Environment

currently content is at closed environment

• Dash.js version: 4.7.4
• Browser name/version: Firefox but issue looks like not depend from browser.
• OS name/version: Ubuntu 23.04

Steps to reproduce

1. Please provide clear steps to reproduce your problem
   you had to have CEA608 closed caption which are displayed at the lowest line at bottom.

2. If the bug is intermittent, give a rough frequency if possible,
   Bug has 100% reproduction in given circumstances ( issue is not observed if browser view will be changed to full screen mode )

Observed behavior

CEA-608 closed captions partially is displayed out of viewable screen.

Expected behavior

CEA-608 closed captions should be displayed on viewable screen.