[Autocomplete] with integers as options throw candidate.toLowerCase error

Please see codesandbox at https://codesandbox.io/s/material-demo-ldh7x?file=/demo.js

• 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 😯

When an autocomplete options prop is only integers, the following error comes:

useAutocomplete.js:44 Uncaught TypeError: candidate.toLowerCase is not a function
    at useAutocomplete.js:44
    at Array.filter (<anonymous>)
    at useAutocomplete.js:40
    at useAutocomplete (useAutocomplete.js:219)
    at Autocomplete (Autocomplete.js:379)
    at renderWithHooks (react-dom.development.js:14803)
    at updateForwardRef (react-dom.development.js:16816)
    at beginWork (react-dom.development.js:18645)
    at HTMLUnknownElement.callCallback (react-dom.development.js:188)
    at Object.invokeGuardedCallbackDev (react-dom.development.js:237)

Expected Behavior 🤔

The expected behaviour is to have the autocomplete showing the integers as options and returning them as a result.

Steps to Reproduce 🕹

https://codesandbox.io/s/material-demo-ldh7x?file=/demo.js

[ShwetaPatel1]

For me the issue was labels as integer.

const KEY_OPTIONS = [{value: 1, label: 1}, {value: 2, label: 2}, {value: 3, label: '3+'}];

I resolved like this. getOptionLabel={(option) => option.label.toString()}

[ShwetaPatel1]

Asking as a user and not as a contributor. I am facing this issue. How do I solve this?