[DateTimePicker] showToolbar default value is true, should be false

[timonla]

Duplicates

• I have searched the existing issues

Latest version

• I have tested the latest version

Current behavior 😯

The default value for showToolbar is true.

Expected behavior 🤔

The default value should be false like the documentation suggests.

Steps to reproduce 🕹

1. Look at the documentation of any DateTimePicker component (https://mui.com/api/desktop-date-time-picker/)
2. It says that showToolbar is false by default
3. See actual default value here: https://codesandbox.io/s/priceless-haslett-vg1bi?file=/src/Demo.tsx

Context 🔦

This is an issue with DateTimePicker, MobileDateTimePicker and DesktopDateTimePicker. It seems to work as specified in documentation for DatePicker and TimePicker components.

Your environment 🌎

`npx @mui/envinfo`

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  Output from `npx @mui/envinfo` goes here.

[alisasanib]

Hi! May I work on it?

[narekmal]

Hi! Can I take this issue?

[flaviendelangle]

Sorry for the delay, I applioed your pull request on the new package in #4451