fix(ios): keep media playing when record

[ratson]

Platforms affected

iOS

Motivation and Context

Set the avSession.category to AVAudioSessionCategoryPlayAndRecord, so media is not stopped when start recording, which matches the recording behavior as Android.

Description

Set the avSession.category to AVAudioSessionCategoryPlayAndRecord.

Testing

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary