Theme: TypeScript support missing for palette.action properties

[timonkbd]

• The issue is present in the latest release.
• I have searched the issues of this repository and believe that this is not a duplicate.

Current Behavior 😯

The following properties of palette.action are exported in src/styles/createPalette.js, but the related TypeScript declaration file (createPalette.d.ts) is missing some of them:

https://github.com/mui-org/material-ui/blob/e02abe51ce16ad1cd3d0af95c77e76d5625c82e8/packages/material-ui/src/styles/createPalette.js#L33-L51

https://github.com/mui-org/material-ui/blob/e02abe51ce16ad1cd3d0af95c77e76d5625c82e8/packages/material-ui/src/styles/createPalette.d.ts#L13-L20

selectedOpacity, disabledOpacity, focus, focusOpacity , activatedOpacity are missing.

Expected Behavior 🤔

The TypeScript definition for TypeAction should look like this:

export interface TypeAction {
  active: string;
  hover: string;
  hoverOpacity: number;
  selected: string;
  selectedOpacity: number;
  disabled: string;
  disabledOpacity: number;
  disabledBackground: string;
  focus: string;
  focusOpacity: number;
  activatedOpacity: number;
}

Context 🔦

As the TypeScript support is missing, the affected properties cannot be used in strict TypeScript environments. I can try to create an PR for that, but I’m new to Material-UI, so I’m not exactly sure if this is a mistake or by purpose.

Your Environment 🌎

Tech	Version
Material-UI	v4.9.5