fix(media_player): update volume down button mappings for improved fu…

[olvrb]

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Proposed change*

Documentation suggests that button down short press maps to volume down. It does not, and this PR contains the correct binding.

Checklist*

• I followed sections of the Contribution Guidelines relevant to changes I'm proposing.
• I properly tested proposed changes on my system and confirm that they are working as expected.
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[yarafie]

@olvrb

I'm not sure if this PR will get approved and folded into the repo, EPMatt has not been around for a while it seems.

However, I folded in your updates to my fork, version 2026.02.17.
My fork is based on EPMatt's but with a few tweaks.

Direct links to this specfic controllers and media_player hook pages below.

https://yarafie.github.io/awesome-ha-blueprints/docs/blueprints/controllers/ikea_e2201/EPMatt/awesome/2026.02.17

https://yarafie.github.io/awesome-ha-blueprints/docs/blueprints/hooks/media_player/EPMatt/awesome/2026.02.17