fix(modal): card modal shadow now shows up correctly on ipad

[liamdebeasi]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

With the new inline modals, we need to make sure that subsequent modals do not have a boxshadow/backdrop shown otherwise the screen will get progressively darker. This rule should only apply to non-card and non-sheet modals, but the selector was a bit too broad. The end result was boxshadows were hidden on all card modals on iPad.

Also there was a box shadow being applied to both the wrapper and shadow element which made the shadow appear to stack.

We did not have visual regression tests for these kinds of stacked modals, so this issue slipped through.

What is the new behavior?

• Shadows are now shown correctly on the card modal on iPad.
• Removed double box shadow.
• Added visual regression tests.

Does this introduce a breaking change?

• Yes
• No

Other information

[sean-perkins]

Lgtm 👍