[Modal] Fix container's width

[mickaelzhang]

WHY are these changes introduced?

There is currently an issue with the Modal's width as it doesn't take into account the scroll bar when visible.

WHAT is this pull request doing?

I've changed the value from vw to % as this one take the scroll bar into account

🎩 checklist

• Tested on mobile
• Tested on multiple browsers
• Tested for accessibility
• Updated the component's README.md with documentation changes
• Tophatted documentation changes in the style guide
• For visual design changes, pinged one of @ HYPD, @ mirualves, @ sarahill, or @ ry5n to update the Polaris UI kit

[ghost]

👋 Thanks for opening your first pull request. A contributor should give feedback soon. If you haven’t already, please check out the contributing guidelines.

[dpersing]

Hi @mickaelzhang! Thanks so much for contributing. While we take a look at your PR, could you review and sign our Contributor License Agreement (CLA)? That will need to be complete before we can merge any PRs. Thanks!

[mickaelzhang]

Hi @dpersing! Yes sorry, I just saw that I needed to sign the CLA. It should be done now 👍

[dleroux]

Hi @mickaelzhang,

Just tested and it works great. I would love to approve but it doesn't show that the CLA has been signed. Can you double-check? We'll also need a UNRELEASED.md entry before we can ship as well.

[mickaelzhang]

@dleroux Weird 🤔 It says that I already signed it

I'll add the entry in UNRELEASED.md when I have a bit of time :)

[dleroux]

That is strange. I'll investigate and get back to you. Thanks!

[mickaelzhang]

@dleroux I made the update on the UNRELEASED.md! I think I just needed to push something, seems fine now for the CLA :)

[ghost]

🎉 Thanks for your contribution to Polaris React!