Carbon: Dropdown issues prop type warning for tabIndex on nested ListBoxField component

[austinbruch]

Rendering the Dropdown component emits a console warning about the tabIndex prop on a nested ListBoxField component.

What package(s) are you using?

• [X] carbon-components
• [X] carbon-components-react

Detailed description

Describe in detail the issue you're having.

Rendering the Dropdown component emits a console warning about the tabIndex prop on a nested ListBoxField component.

Is this issue related to a specific component?

Dropdown

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

No prop type warning that is outside my control.

What browser are you working in?

Chrome

What version of the Carbon Design System are you using?

carbon-components 10.4.1
carbon-components-react 7.4.1

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

Steps to reproduce the issue

Render a Dropdown component.

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/codesandbox-shklr

Additional information

Console warning:

Warning: Failed prop type: Invalid prop `tabIndex` of value `0` supplied to `ListBoxField`, expected one of [null,null].
    in ListBoxField (created by Downshift)

    in Downshift (created by Dropdown)

    in div (created by Dropdown)

    in Dropdown (created by App)

    in div (created by App)

    in App

[jendowns]

Hey @austinbruch just a heads up -- I addressed this in PR #3425 but it wasn't automatically closed out because I didn't reference this issue number correctly in my desc 😇

[austinbruch]

Thanks, Jen.