List widget required not working

**Describe the bug**
A list with required field set to true and not detected when post save

**To Reproduce**
Steps to reproduce the behavior. For example:
1. Have a list widget like this one:
`- {
label: 'Gallery',
name: 'galleryImages',
widget: 'list',
summary: '{{field.image}}',
required: true,
collapsed: false,
min: 1,
field: { label: Image, name: image, widget: image, required: true },
}`
2. Click on Save
3. Not detecting the required field and allow to save the post

**Expected behavior**

When save the post and this list widget is empty should show a red border like it happens with a text field for example and not allow to save if it's empty