icon: remove icon round background (align with innertune)

[mattcarter11]

What is it?

• New feature (user facing)
• Update to existing feature (user facing)
• Bugfix (user facing)
• Translations
• Codebase improvements or refactors (dev facing)
• Other

Description of the changes in your PR

• Remove round background in player buttons to align better with innertune and not distract

Before/After Screenshots/Screen Record

Due diligence

• I read the contribution guidelines.
• I understand that in the event of merge conflicts, I may be asked to rebase my branch on top of the dev branch, instead of resolving them by merging dev into my own branch

[DD3Boh]

I'm worried about this possibly creating more contrast issues with gradient and blur backgrounds, since we support those as well.

[aqqlqlql]

I'm worried about this possibly creating more contrast issues with gradient and blur backgrounds, since we support those as well.

It will probably be fine.