message: fix(footer): add carbon button style under theme mixin
diff: //
  @import '../../temp-carbon-expressive/button/button-expressive';
  +@import 'carbon-components/scss/components/button/button';
  /// Footer locale button
  /// @access private
  @include exports('local-button') {
  @include carbon--theme($carbon--theme--g90) {
  + @include button;
  @include local-button;
  }
  }
  