TextArea react component not inheriting the width from it's container

[nicoxxie]

What package(s) are you using?

• carbon-components
• carbon-components-react

Detailed description

Describe in detail the issue you're having.
Text area is not inherting it's parent's width which is the set through className props on the component.

It used to on v9

Is this issue related to a specific component?
TextArea

What did you expect to happen? What happened instead? What would you like to
see changed?
can control the width

What browser are you working in?
Chrome Version 79.0.3945.88 (Official Build) (64-bit)

What version of the Carbon Design System are you using?
carbon-components-react: 7.9.0
carbon-components: 10.9.0

What offering/product do you work on? Any pressing ship or release dates we
should be aware of?
IBM Cloud

Steps to reproduce the issue

1. Step one
2. Step two
3. Step three
4. etc.

Please create a reduced test case in CodeSandbox

• Style and vanilla JS:
  https://codesandbox.io/s/github/carbon-design-system/carbon/tree/master/packages/components/examples/codesandbox
• React:
  https://codesandbox.io/s/github/carbon-design-system/carbon/tree/master/packages/react/examples/codesandbox

https://codesandbox.io/s/dawn-snow-2zc94

Additional information

• Screenshots or code
• Notes

[jendowns]

I can help with this one 👍
Just opened a small PR here: #4995