Ability to pick between Icon and Entity Picture in Media Players

[aacienfuegos]

Is your feature request related to a problem? Please describe.
When I select a Media Player, I can't have the icon instead of the entity picture. I have multiple media speakers which I differentiate using icons (like a sofa for the one in the living room and things like that), but when using this button the album cover is shown instead of the icon and we don't have the ability to pick which of the two we want.

Describe the solution you'd like
A simple boolean option in the configuration would be enough to pick between showing the entity picture or the icon. Instead of only checking if there is an entity picture, you'd check also for this boolean when rendering the button.

Describe alternatives you've considered
The alternative to this is not having the icon at all and use the name of the entity to know which speaker tye button is for. However I believe dashboards with icons instead of text are much easier to use and in smaller screens having all the names of the speakers is not even possible.

Additional context
Not needed.

[aacienfuegos]

I can help with the JS but I'm not so familiar with all the home assistant stuff (such as the UI menu to configure the button).