add initializer with default nil for customer

Author: KunJeongPark

Demo/Demo/Models/CreateOrderParams.swift

@@ -63,6 +63,11 @@ struct Attributes: Encodable {
 
     let vault: Vault
     let customer: VaultCustomer?
+
+    init(vault: Vault, customer: VaultCustomer? = nil) {
+        self.vault = vault
+        self.customer = customer
+    }
 }
 
 struct Vault: Encodable {

Demo/Demo/ViewModels/PayPalWebViewModel.swift

@@ -28,8 +28,7 @@ class PayPalWebViewModel: ObservableObject, PayPalWebCheckoutDelegate {
                     storeInVault: "ON_SUCCESS",
                     usageType: "MERCHANT",
                     customerType: "CONSUMER"
-                ),
-                customer: nil as VaultCustomer?
+                )
             )
             let paypal = VaultPayPal(attributes: attributes, experienceContext: ExperienceContext(returnURL: "https://example.com/returnUrl", cancelURL: "https://example.com/cancelUrl"))
             vaultPayPalPaymentSource = VaultPayPalPaymentSource(paypal: paypal)