Use property model's language in IAMs

* IAMs were never updated to use the app defined setLanguage feature previously.
* Now use the language from the user's property model to get variantId for an IAM. If this is null on the user, the IAM will still recover by going to the `default` variant.
* Tested with different IAMs with different variants

Author: nan-li

iOS_SDK/OneSignalSDK/OneSignalUser/Source/OneSignalUserManagerImpl.swift

@@ -97,6 +97,10 @@ public class OneSignalUserManagerImpl: NSObject, OneSignalUserManager {
     @objc public var pushSubscriptionId: String? {
         return _user?.pushSubscriptionModel.subscriptionId
     }
+    
+    @objc public var language: String? {
+        return _user?.propertiesModel.language
+    }
 
     private var hasCalledStart = false
 

iOS_SDK/OneSignalSDK/Source/OSInAppMessageController.m

@@ -27,6 +27,7 @@
 
 #import "OSInAppMessageController.h"
 #import <OneSignalCore/OneSignalCore.h>
+#import <OneSignalUser/OneSignalUser.h>
 #import "OSInAppMessagingDefines.h"
 #import "OSInAppMessagingRequests.h"
 
@@ -38,7 +39,7 @@ - (void)loadMessageHTMLContentWithResult:(OSResultSuccessBlock _Nullable)success
 
     if (!variantId) {
         if (failureBlock)
-            failureBlock([NSError errorWithDomain:@"onesignal" code:0 userInfo:@{@"error" : [NSString stringWithFormat:@"Unable to find variant ID for languages (%@) for message ID: %@", NSLocale.preferredLanguages, self.messageId]}]);
+            failureBlock([NSError errorWithDomain:@"onesignal" code:0 userInfo:@{@"error" : [NSString stringWithFormat:@"Unable to find variant ID for languages (%@) for message ID: %@", OneSignalUserManagerImpl.sharedInstance.language, self.messageId]}]);
 
         return;
     }
@@ -62,20 +63,16 @@ variant over lower platforms (ie. 'all') even if they have a
     matching language.
 */
 - (NSString * _Nullable)variantId {
-    let isoLanguageCodes = [NSLocale preferredLanguages];
+    // we only want the first two characters, ie. "en-US" we want "en"
+    NSString *userLanguageCode = [OneSignalUserManagerImpl.sharedInstance.language substringToIndex:2];
 
     NSString *variantId;
 
     for (NSString *type in PREFERRED_VARIANT_ORDER) {
         if (self.variants[type]) {
-            for (NSString *code in isoLanguageCodes) {
-                // we only want the first two characters, ie. "en-US" we want "en"
-                let isoLanguageCode = [code substringToIndex:2];
-                
-                if (self.variants[type][isoLanguageCode]) {
-                    variantId = self.variants[type][isoLanguageCode];
-                    break;
-                }
+            if (self.variants[type][userLanguageCode]) {
+                variantId = self.variants[type][userLanguageCode];
+                break;
             }
 
             if (!variantId && self.variants[type][@"default"]) {

iOS_SDK/OneSignalSDK/Source/OSMessagingController.m

@@ -30,7 +30,6 @@
 #import "UIApplication+OneSignal.h" // Previously imported via "OneSignalHelper.h"
 #import "NSDateFormatter+OneSignal.h" // Previously imported via "OneSignalHelper.h"
 #import <OneSignalCore/OneSignalCore.h>
-#import "OneSignalInternal.h"
 #import "OSInAppMessageAction.h"
 #import "OSInAppMessageController.h"
 #import "OSInAppMessagePrompt.h"
@@ -317,7 +316,7 @@ - (void)onDidDismissInAppMessage:(OSInAppMessageInternal *)message {
 
 - (void)presentInAppMessage:(OSInAppMessageInternal *)message {
     if (!message.variantId) {
-        let errorMessage = [NSString stringWithFormat:@"Attempted to display a message with a nil variantId. Current preferred language is %@, supported message variants are %@", NSLocale.preferredLanguages, message.variants];
+        let errorMessage = [NSString stringWithFormat:@"Attempted to display a message with a nil variantId. Current preferred language is %@, supported message variants are %@", OneSignalUserManagerImpl.sharedInstance.language, message.variants];
         [OneSignalLog onesignalLog:ONE_S_LL_ERROR message:errorMessage];
         return;
     }