message: Created appearance if nil
  The scrollEdgeAppearance is nil (the others weren't?!) which stopped the bar tint being applied when search expanded
diff: -(UINavigationBarAppearance *)updateColors:(UINavigationBarAppearance *)appearance
  API_AVAILABLE(ios(13.0))
  {
  - UINavigationBarAppearance *appearanceCopy = [appearance copy];
  + UINavigationBarAppearance *appearanceCopy = appearance != nil ? [appearance copy] : [UINavigationBarAppearance new];
  [appearanceCopy setBackgroundColor:self.barTintColor];
  [appearanceCopy.buttonAppearance.normal setTitleTextAttributes:[self setForeground:self.tintColor :appearanceCopy.buttonAppearance.normal.titleTextAttributes]];
  [appearanceCopy.doneButtonAppearance.normal setTitleTextAttributes:[self setForeground:self.tintColor :appearanceCopy.doneButtonAppearance.normal.titleTextAttributes]];
  