[Datagrid] Checkbox checked when no rows

[bigandy]

• 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 there are rows i.e. rows={[]} the checkbox is checked

Expected Behavior 🤔

If there are no rows the checkbox should not be checked

Steps to Reproduce 🕹

https://codesandbox.io/s/material-demo-forked-x1phw?file=/demo.tsx

Steps:

1.<DataGrid checkboxSelection columns={data.columns} rows={[]} />
2.Notice that the checkbox is checked

Your Environment 🌎

"dependencies": {
"@emotion/react": "11.1.5",
"@emotion/styled": "11.1.5",
"@material-ui/core": "5.0.0-alpha.25",
"@material-ui/data-grid": "4.0.0-alpha.20",
"@material-ui/icons": "latest",
"@material-ui/lab": "latest",
"@material-ui/x-grid-data-generator": "latest",
"@types/react": "latest",
"@types/react-dom": "latest",
"react": "latest",
"react-dom": "latest",
"typescript": "latest"
}
see https://codesandbox.io/s/material-demo-forked-x1phw

Order id 💳

[bigandy]

@dtassone is it okay if I make a PR to fix it?