Button: wired spacing when line breaks

• 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 😯

There is additional space on the button left and right (see screenshot)

Expected Behavior 🤔

The button should shrink as without line breaks

Steps to Reproduce 🕹

Steps:

1. Please note the maxWidth on the surrounding div.
2. https://codesandbox.io/s/material-demo-3do1p?file=/demo.js

<div style={{ maxWidth: 170 }}>
    <Button variant="contained" color="primary">
        Send to somewhere
    </Button>
    <Button variant="contained" color="primary">
        Send to some
    </Button>
</div>

Context 🔦

THis issue might be related: https://github.com/mui-org/material-ui/issues/17494

Your Environment 🌎

Tech	Version
Material-UI	v4.9.9
React	16.13.1
Browser	Linux Chrome Version 80.0.3987.162 (Official Build) (64-bit)
TypeScript
etc.

[oliviertassinari]

Tip, check the full-width option

[RobertHeim]

The button stops shrinking.