With this change, composable previews and screenshots should be created with just:
```
@ElementPreviews
@Composable
fun MyViewPreview() {
ElementPreview {
MyView()
}
}
```
- Adds `@ElementPreviews` which is a shorthand for:
```
@Preview(name = "D")
@Preview(name = "N", uiMode = Configuration.UI_MODE_NIGHT_YES)
```
Should be used in connection with the now public `fun ElementPreview()` composable.
- Adds ElementPreviews to previewAnnotations in dangerfile
- Screenshots of night mode previews are now rendered with night mode
- Replaces `ElementPreviewLight` and `ElementThemedPreview` with `ElementPreview`
- Deprecates `ElementPreviewDark` which should be removed.
- Remaining usages of `ElementPreviewDark` are now ignored during screenshot tests
