Fix: File block add custom class (#13432)

## Description
The custom class should only be added to the wrapper, not every div
Fixes #13430

packages/block-library/src/file/edit.js

@@ -184,9 +184,9 @@ class FileEdit extends Component {
  </MediaUploadCheck>
  </BlockControls>
  <div className={ classes }>
- <div className={ `${ className }__content-wrapper` }>
+ <div className={ 'wp-block-file__content-wrapper' }>
  <RichText
- wrapperClassName={ `${ className }__textlink` }
+ wrapperClassName={ 'wp-block-file__textlink' }
  tagName="div" // must be block-level or else cursor disappears
  value={ fileName }
  placeholder={ __( 'Write file name…' ) }
@@ -195,11 +195,11 @@ class FileEdit extends Component {
  onChange={ ( text ) => setAttributes( { fileName: text } ) }
  />
  { showDownloadButton &&
- <div className={ `${ className }__button-richtext-wrapper` }>
+ <div className={ 'wp-block-file__button-richtext-wrapper' }>
  { /* Using RichText here instead of PlainText so that it can be styled like a button */ }
  <RichText
  tagName="div" // must be block-level or else cursor disappears
- className={ `${ className }__button` }
+ className={ 'wp-block-file__button' }
  value={ downloadButtonText }
  formattingControls={ [] } // disable controls
  placeholder={ __( 'Add text…' ) }
@@ -213,7 +213,7 @@ class FileEdit extends Component {
  <ClipboardButton
  isDefault
  text={ href }
- className={ `${ className }__copy-url-button` }
+ className={ 'wp-block-file__copy-url-button' }
  onCopy={ this.confirmCopyURL }
  onFinishCopy={ this.resetCopyConfirmation }
  disabled={ isBlobURL( href ) }