Text track roles are being incorrectly combined in certain multi-period cases

[littlespex]

Have you read the FAQ and checked for duplicate open issues?
Yes

If the problem is related to FairPlay, have you read the tutorial?

N/A

What version of Shaka Player are you using?

4.6.6, 4.7.2

Can you reproduce the issue with our latest release version?
Yes

Can you reproduce the issue with the latest code from main?
Yes

Are you using the demo app or your own custom app?
Both

If custom app, can you reproduce the issue using our demo app?
Yes

What browser and OS are you using?
Chrome / MacOS

For embedded devices (smart TVs, etc.), what model and firmware version are you using?
N/A

What are the manifest and license server URIs?

Sent separately

What configuration are you using? What is the output of player.getConfiguration()?

Default

What did you do?

1. Load a multi-period manifest with multi language audio, text tracks, and forced subtitle tracks. One period must not contain the forced subtitle track/adaptation set.
2. Call getTextTracks()

What did you expect to happen?
Each text track should have a single role, either 'subtitle' or 'forced-subtitle'.

What actually happened?

The text track roles are combined into resulting in one of the tracks having both 'subtitle' and 'forced-subtitle' roles.