Updated CSS media query to better detect touch devices

[timsluis]

This pull request addresses an issue where the MobileHelpText for cooperative gestures is incorrectly displayed when a map is embedded in an iFrame with a width smaller than 480px, even if the user is on a desktop device.

This PR closes #5052

Launch Checklist

• Confirm your changes do not include backports from Mapbox projects (unless with compliant license) - if you are not sure about this, please ask!
• Briefly describe the changes in this PR.
• Link to related issues.
• Write tests for all new functionality.
• Add an entry to CHANGELOG.md under the ## main section.

[timsluis]

@HarelM Do we need/should I write a test for this?

[HarelM]

THANKS!

[HarelM]

Since this is a trivial CSS change I don't see a lot of value adding a test here...