Desktop sound notification not playing when account preference not overridden

Description:

It seems sound notification for a new message is not played when only account preference is set (and per channel is "default").

Steps to reproduce:

1. In your account preferences, in Sound section, check new message notification option. I have for example "Chime".
2. Go to a channel and in its notification preferences.
3. Check in Desktop, that audio option is not set to never play sound.
4. Check in Desktop, that sound selection is Default.
5. Result : New message don't play the sound. (NOK)

Then :

1. Go back to the channel and in its notification preferences.
2. Choose another sound in Desktop > Sound (for example Seasons).
3. Result : New message do play the selected sound. (OK)

Then :

1. Go back to the channel and its notification preferences.
2. Choose default for Desktop > Sound.
3. Go to your account preferences, in Sound section.
4. Select another sound in new message notification option (for example Seasons).
5. Résult : New message don't play the sound. (NOK)

Expected behavior:

The sound set in account preferences should play even if not overridden in channel preferences.

Actual behavior:

See "Steps to reproduce".

Server Setup Information:

• Version of Rocket.Chat Server: 3.13.1
• Operating System: Linux

Client Setup Information

• Desktop App or Browser Version: Firefox ESR and Chromium

Start by reproducing the notification behavior with an account sound selected and the channel sound set to Default, then trace how those preferences are resolved for new-message notifications. Done means the account-level sound plays when the channel does not override it, while an explicit channel sound still plays its selected sound.