Minor style updates, fixing the "combined" steps provider

[chrisnowak]

Overview

This takes a few of the style updates I had applied separately in #110 so I could release them more quickly. It also fixes the "combined" steps provider; currently it errors if you don't have garmin or fitbit enabled for your study. So it now checks the data collection status.

The style updates are mostly tweaking the default border radius to 12px and tweaks the default dropshadow based on some of the designs @kyledehovitz-ce has been putting out lately; so things can stay consistent / aligned.

It also changes the line-height to 1.2 instead of 1.2em, so it's applied consistently across the page (I forgot how this worked; 1.2em just sets it statically whereas 1.2 is relative to font size of the element) as this fixes an acute issue with titles in the view builder.

Security

REMINDER: All file contents are public.

• I have ensured no secure credentials or sensitive information remain in code, metadata, comments, etc.
  • Please verify that you double checked that .storybook/preview.js does not contain your participant access key details.
  • There are no temporary testing changes committed such as API base URLs, access tokens, print/log statements, etc.
• These changes do not introduce any security risks, or any such risks have been properly mitigated.

Describe briefly what security risks you considered, why they don't apply, or how they've been mitigated.

Checklist

Testing

• MyDataHelps iOS app
• MyDataHelps Android app
• MyDataHelps website

Documentation

• I have added relevant Storybook updates to this PR as well.
• If this feature requires a developer doc update, tag @CareEvolution/api-docs.

Consider "Squash and merge" as needed to keep the commit history reasonable on main.

Reviewers

Assign to the appropriate reviewer(s). Minimally, a second set of eyes is needed ensure no non-public information is published. Consider also including:

• Subject-matter experts
• Style/editing reviewers
• Others requested by the content owner