[TextareaAutosize] Export component in barrel index.js (#17003)

Fixes #17002 

@joshwooding

packages/material-ui/src/index.js

@@ -118,6 +118,7 @@ export { default as TableRow } from './TableRow';
 export { default as TableSortLabel } from './TableSortLabel';
 export { default as Tabs } from './Tabs';
 export { default as TextField } from './TextField';
+export { default as TextareaAutosize } from './TextareaAutosize';
 export { default as Toolbar } from './Toolbar';
 export { default as Tooltip } from './Tooltip';
 export { default as Typography } from './Typography';