Update ChoiceList mobile styles

[lgriffee]

WHY are these changes introduced?

Fixes https://github.com/Shopify/polaris-internal/issues/1590
Fixes https://github.com/Shopify/mobile/issues/33785

Caution

Basing this PR off of #11837 and will not merge until that ships. No need to include changes from #11878 since the helper/error text changes do not factor into clickable area.

WHAT is this pull request doing?

• Increases Choice padding so the tap target on mobile is 48px
• Improves ChoiceList mobile padding

Before	After

How to 🎩

Tip

Make sure you have the breakpoint in storybook at sm or xs to see the changes!

• 📕 Storybook Before
• 📕 Storybook After

[lgriffee]

/snapit

[github-actions]

🫰✨ Thanks @lgriffee! Your snapshothas been published to npm.

Test the snapshot by updating your package.json with the newly published version:

"@shopify/polaris": "0.0.0-snapshot-20240416230446"

[aveline]

Looks good overall! Just one question about the indentation of the children content, I noticed it's updated to now be in line with the radio button, is that intentional? I didn't see an example in the Figma.

[lgriffee]

Looks good overall! Just one question about the indentation of the children content, I noticed it's updated to now be in line with the radio button, is that intentional? I didn't see an example in the Figma.

@aveline Yes, it was an intentional change based on these mockups in Figma. Would be good to confirm with @heyjoethomas this is still the desired design update!

[lgriffee]

Closing in favor of build phase PR