fix(typescript): type checks on selectedTextTrack, selectedAudioTrack, selectedVideoTrack

[Polarisation]

Summary

Fix type checks on selectedTextTrack, selectedAudioTrack and selectedVideoTrack properties which were added in #3704.

Motivation

selectedTextTrack, selectedAudioTrack and selectedVideoTrack can both be an object with a type property and an undefined value. This allows react-native-video to distinguish between disabled subtitles and subtitles following system settings.

However this behavior was broken by the addition of an incorrect type check in #3704 which does not allow the value property to be undefined.

Changes

Adapted the type check to allow value property to be undefined, as per documentation and TypeScript type definitions.

Test plan

[freeboub]

thank you for the patch, I am just proposing you to improve the log. I let you integrate the change

[Polarisation]

@freeboub Thank you, I made those changes. I also applied the same fix to selectedVideoTrack as I noticed this had the same bug.

[freeboub]

@freeboub Thank you, I made those changes. I also applied the same fix to selectedVideoTrack as I noticed this had the same bug.

You are right, thank you !