[MOB-10364] Update according to new discussiom

Author: sumeruchat

swift-sdk/Internal/in-app/InAppPersistence.swift

@@ -308,11 +308,6 @@ extension IterableInAppMessage: Codable {
         // Encode jsonOnly first
         try? container.encode(isJsonOnly ? 1 : 0, forKey: .jsonOnly)
 
-        // Don't encode if JSON-only message without customPayload
-        if isJsonOnly && customPayload == nil {
-            return
-        }
-        
         try? container.encode(trigger, forKey: .trigger)
         try? container.encode(saveToInbox && !isJsonOnly, forKey: .saveToInbox)
         try? container.encode(messageId, forKey: .messageId)

tests/unit-tests/InAppPersistenceTests.swift

@@ -159,7 +159,7 @@ class InAppPersistenceTests: XCTestCase {
             XCTAssertTrue(jsonData["content"] == nil || (jsonData["content"] as? [String: Any])?.isEmpty == true)
         }
 
-        // Test 3: Message without customPayload
+        // Test 3: Message without customPayload should now persist normally
         let messageWithoutPayload = IterableInAppMessage(
             messageId: "test-json-2",
             campaignId: 456,
@@ -178,7 +178,18 @@ class InAppPersistenceTests: XCTestCase {
         persister.clear()
         persister.persist([messageWithoutPayload])
         let retrievedEmptyMessages = persister.getMessages()
-        XCTAssertEqual(retrievedEmptyMessages.count, 1, "JSON-only messages without customPayload should still be persisted")
+        XCTAssertEqual(retrievedEmptyMessages.count, 1)
+        
+        guard let retrievedEmptyMessage = retrievedEmptyMessages.first else {
+            XCTFail("No message retrieved")
+            return
+        }
+        
+        // Verify properties of message without customPayload
+        XCTAssertEqual(messageWithoutPayload.messageId, retrievedEmptyMessage.messageId)
+        XCTAssertEqual(messageWithoutPayload.campaignId?.intValue, retrievedEmptyMessage.campaignId?.intValue)
+        XCTAssertTrue(retrievedEmptyMessage.jsonOnly)
+        XCTAssertNil(retrievedEmptyMessage.customPayload)
 
         // Test 4: Array of JSON-only messages
         let messagesArray = [