update OneSignalIdentifiers to read from resilient storage

Author: nan-li

iOS_SDK/OneSignalSDK/OneSignalOSCore/Source/OneSignalIdentifiers.swift

@@ -47,13 +47,22 @@ public final class OneSignalIdentifiers: NSObject {
         set { lock.withLock { _currentAppId = newValue } }
     }
 
-    /// Last-known persisted `app_id` from shared UserDefaults. Returns nil if absent.
+    /// Persisted `app_id` from shared UserDefaults first, then the unencrypted `OSResilientStorage` mirror,
+    /// covering the prewarm-before-first-unlock window where UserDefaults is locked and silently returns nil.
     @objc public static var storedAppId: String? {
-        return OneSignalUserDefaults.initShared().getSavedString(forKey: OSUD_APP_ID, defaultValue: nil)
+        if let fromUD = OneSignalUserDefaults.initShared().getSavedString(forKey: OSUD_APP_ID, defaultValue: nil),
+           !fromUD.isEmpty {
+            return fromUD
+        }
+        return OSResilientStorage.string(forKey: OSResilientStorage.keyAppId)
     }
 
-    /// Persisted push `subscription_id` from shared UserDefaults. Returns nil if absent.
+    /// Persisted push `subscription_id` from shared UserDefaults first, then the unencrypted `OSResilientStorage` mirror.
     @objc public static var subscriptionId: String? {
-        return OneSignalUserDefaults.initShared().getSavedString(forKey: OSUD_PUSH_SUBSCRIPTION_ID, defaultValue: nil)
+        if let fromUD = OneSignalUserDefaults.initShared().getSavedString(forKey: OSUD_PUSH_SUBSCRIPTION_ID, defaultValue: nil),
+           !fromUD.isEmpty {
+            return fromUD
+        }
+        return OSResilientStorage.string(forKey: OSResilientStorage.keySubscriptionId)
     }
 }