NumberInput: uncontrolled NumperInput not respecting defaultValue

[ashharrison90]

What package(s) are you using?

• carbon-components
• carbon-components-react

Detailed description

Describe in detail the issue you're having.

• Using NumberInput as an uncontrolled component with defaultValue does not set the defaultValue correctly, and throws a warning in the console about using both value and defaultValue simultaneously

Is this issue related to a specific component?

• NumberInput

What did you expect to happen? What happened instead? What would you like to
see changed?

• expected it to display the defaultValue correctly
• expected it to not throw a warning in the console about having value and defaultValue set simultaneously

What browser are you working in?

• chrome 86.0.4240.198

What version of the Carbon Design System are you using?

• [email protected]

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

• IBM App Connect

Steps to reproduce the issue

1. Use NumberInput with a defaultValue

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/nifty-framework-pxzh7

Additional information

• probably due to always setting value here: https://github.com/carbon-design-system/carbon/blob/master/packages/react/src/components/NumberInput/NumberInput.js#L325. i think this should only set value if it's a controlled component.