feat: implement opacity to control visibility of subtitles

[coofzilla]

Summary

Add ability to control subtitle visibility while still maintaining ability of selecting a text track.

Motivation

see #3579

Changes

Updated subtitleStyle to include an opacity property; which, can control the visibility of subtitles.

Updated documentation for the new property and provided a link onTextTrackDataChanged -> subtitleStyles to clarify intent on how to control visibility of subtitles.

Test plan

✅ Tested on example app:

Simply set the following props:

          selectedTextTrack={{
            type: SelectedTrackType.LANGUAGE,
            value: 'en',
          }}
          subtitleStyle={{
            opacity: 0,
          }}

Then observe that the subtitleTracks log from onTextTrackDataChanged and do not display them :)

Subtitles displayed as expected when set to 1:

If not explicitly set, they will be displayed:

Type safe, must be 0 or 1

[coofzilla]

@KrzysztofMoch I believe the build android actions need their cache cleaned and re-run they passed https://github.com/react-native-video/react-native-video/actions/workflows/build-android.yml right before I did the lint to remove a white space.

[coofzilla]

#3580 seems like this might be related.

[freeboub]

please see my comment.
I think you can also add the ios change in this PR ?!

[coofzilla]

I think you can also add the ios change in this PR ?!

actually, yeah I can add those changes, I'm going to update it now.

[coofzilla]

@freeboub Added the ios changes, please review :)

Tested:

✅ Opacity set to 0:

✅ Opacity set to 0.5( not supported; but, no errors ) this is due to limitations with alpha support on legibleOutput:

✅ Opacity set to 1:

[coofzilla]

and one more verification for good measure.

tested with:

  selectedTextTrack={{
    type: SelectedTrackType.LANGUAGE,
    value: 'en',
  }}
  subtitleStyle={{
    opacity: 0,
  }}

[KrzysztofMoch]

LGTM 👍

[freeboub]

one small remark, else it looks good to me !

[coofzilla]

one small remark, else it looks good to me !

great catch, thank you! I think the cache needs to be cleared for the Build Android, and then it should be good for merge? 🥹

[freeboub]

@coofzilla Yes this is OK for me!
let's wait for @KrzysztofMoch for the builder cache issue