Custom streams don't trigger subscribe and unsubscribe events

[enricop89]

New issue checklist

• I have read all of the README
• I have searched existing issues and this is not a duplicate.

General information

• Library version(s): 2.0.17
• iOS/Android/Browser version(s): Browser
• Devices/Simulators/Machine affected: all
• Reproducible in the demo project? (Yes/No): yes
• Related issues:

Bug report

When you publish a stream with a custom videoSource (startCall({videoSource:MediaStreamTrack})), the library doesn't send the subscribeToCustom and unsubscribeFromCustom events because they are not handled by the events.js file

Expected behavior

it should trigger the subscribe and unsubscribe events for the custom source

Actual behavior

it doesn't trigger the events.

Steps to reproduce

Run the sample app with otCore .startCall({ videoSource: MediaStreamTrack })