[Sample] Add edgesIgnoringSafeArea to CheckoutSheet for SwiftUI (#375)

Add edgesIgnoringSafeArea(.all) to CheckoutSheet for SwiftUI

Author: markmur

Samples/MobileBuyIntegration/MobileBuyIntegration/Views/CartView.swift

@@ -113,6 +113,7 @@ struct CartView: View {
                             // Handle checkout failure
                             print("Checkout failed: \(error)")
                         }
+                        .edgesIgnoringSafeArea(.all)
                 }
             }
         } else {