[VwG] Add verification flow example to DaysUntilBirthday Sample App.

Samples/Swift/DaysUntilBirthday/Shared/Services/VerificationLoader.swift

@@ -32,7 +32,7 @@ final class VerificationLoader: ObservableObject {
   /// Verifies the user's age based upon the selected account.
   /// - note: Successful calls to this method will set the `verificationState` property of the
   /// `verifiedAgeViewModel` instance passed to the initializer.
-  func verifyAccountDetails() {
+  func verifyUserAge() {
     let accountDetails: [GIDVerifiableAccountDetail] = [
       GIDVerifiableAccountDetail(accountDetailType: .ageOver18)
     ]

Samples/Swift/DaysUntilBirthday/Shared/ViewModels/VerifiedAgeViewModel.swift

@@ -34,14 +34,9 @@ final class VerifiedAgeViewModel: ObservableObject {
     self.verificationState = .unverified
   }
 
-  /// Verifies the user.
-  func verifyAccountDetails() {
-    switch self.verificationState {
-    case .unverified:
-      loader.verifyAccountDetails()
-    case .verified:
-      return
-    }
+  /// Verifies the user's age over 18.
+  func verifyUserAge() {
+    loader.verifyUserAge()
   }
 }
 

Samples/Swift/DaysUntilBirthday/iOS/UserProfileView.swift

@@ -57,7 +57,10 @@ struct UserProfileView: View {
           NavigationLink(NSLocalizedString("Verify My Age", comment: "Verify Age"),
                          destination: VerificationView(verifiedAgeViewModel: verifiedAgeViewModel)
           .onAppear {
-            verifiedAgeViewModel.verifyAccountDetails()
+            verifiedAgeViewModel.verifyUserAge()
+          }
+          .onDisappear {
+            verifiedAgeViewModel.verificationState = .unverified
           })
 #endif
           Spacer()