Update Banner mobile styles

[lgriffee]

WHY are these changes introduced?

Closes https://github.com/Shopify/mobile/issues/33410

WHAT is this pull request doing?

• Removes shadow below sm breakpoint
• Changes styling of banners with titles to match that of InlineIconBanners below sm breakpoint
• Tightens spacing between of action buttons below sm breakpoint
• Makes action buttons take up available space below sm breakpoint

Before (below sm breakpoint)	After (below sm breakpoint)

• 📕 Storybook Before
• 📕 Storybook After

[lgriffee]

Made this change so we can see some examples of buttons side by side instead of stacked on small screens

[davebcn87]

I think we are missing some alignment between the icon and the title. Also, is the title the proper size? feels a bit small to me. Most likely it is because the mobile typography is not yet applied, right?

[lgriffee]

I think we are missing some alignment between the icon and the title. Also, is the title the proper size? feels a bit small to me. Most likely it is because the mobile typography is not yet applied, right?

@davebcn87 Good callout! Definitely agree about the alignment there. I hadn't originally based this PR off the typography updates but your right that it's an important factor in reviewing all the alignment. I've updated the PR do that now (see screenshots above in the PR description), but now the body text looks giant. Not sure if we will need to adjust the Banner font sizes to compensate? Might be worth it for me to book some time with @heyjoethomas to figure out how we want to handle that (or to just bring it up during our Banner meeting tomorrow). In the meantime I'll work on aligning the title better for the InlineIconBanners.

[lgriffee]

@davebcn87 I've updated the title alignment on the InlineIconBanners in 1f08404

[lgriffee]

Closing in favor of build phase PR