Fixes NavBar and TabBar issues on iOS 15 using Xcode 13

fixiOS15AppearanceIssues.swift

  func fixiOS15AppearanceIssues() {
    fixiOS15NavBarIssues()
    fixiOS15TabBarIssues()
  }
    
  private func fixiOS15NavBarIssues() {
    if #available(iOS 15, *) {
      let appearance = UINavigationBarAppearance()
      appearance.configureWithOpaqueBackground()
      appearance.backgroundColor = .blue //customised nav bar background color 
      appearance.shadowColor = .clear //removes the nav bar shadow
      appearance.titleTextAttributes = [.foregroundColor: UIColor.white]
      UINavigationBar.appearance().standardAppearance = appearance
      UINavigationBar.appearance().scrollEdgeAppearance = appearance
    }
  }
    
  private func fixiOS15TabBarIssues() {
    if #available(iOS 15, *) {
      let appearance = UITabBarAppearance()
      appearance.configureWithOpaqueBackground()
      appearance.backgroundColor = .white
      UITabBar.appearance().standardAppearance = appearance
      UITabBar.appearance().scrollEdgeAppearance = appearance
    }
  }