Fix HTTP Race Condition (#372)

* Fix HTTP Concurrency

• Fixes a relatively rare issue that would be encountered if the SDK attempted to make concurrent HTTP requests during an invalid situation, such as after the user has revoked GDPR consent
• The SDK was previously using a semaphore to wait for a batch of HTTP requests to finish.
• However, if the SDK immediately fails the request (synchronously), the request would fail before the SDK started waiting for the request to finish, resulting in a permanently blocked queue.
• Switched to using a dispatch_group which would handle this situation better. Also added a missing GDPR consent check to the onFocus methods

* Remove Debug Statement

• Removes a debug statement from the previous commit

Author: Nightsd01

iOS_SDK/OneSignalSDK/Source/OneSignalClient.m

@@ -72,26 +72,27 @@ - (void)executeSimultaneousRequests:(NSDictionary<NSString *, OneSignalRequest *
 
     //execute on a background thread or the semaphore will block the caller thread
     dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
-        dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);
+        dispatch_group_t group = dispatch_group_create();
 
         __block NSMutableDictionary<NSString *, NSError *> *errors = [NSMutableDictionary new];
         __block NSMutableDictionary<NSString *, NSDictionary *> *results = [NSMutableDictionary new];
 
         for (NSString *identifier in requests.allKeys) {
             let request = requests[identifier];
 
+            //use a dispatch_group instead of a semaphore, in case the failureBlock gets called synchronously
+            //this will prevent the SDK from waiting/blocking on a request that instantly failed
+            dispatch_group_enter(group);
             [self executeRequest:request onSuccess:^(NSDictionary *result) {
                 results[identifier] = result;
-                dispatch_semaphore_signal(semaphore);
+                dispatch_group_leave(group);
             } onFailure:^(NSError *error) {
                 errors[identifier] = error;
-                dispatch_semaphore_signal(semaphore);
+                dispatch_group_leave(group);
             }];
         }
 
-        for (int i = 0; i < requests.count; i++) {
-            dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);
-        }
+        dispatch_group_wait(group, DISPATCH_TIME_FOREVER);
 
         //requests should all be completed at this point
         dispatch_async(dispatch_get_main_queue(), ^{

iOS_SDK/OneSignalSDK/Source/OneSignalTracker.m

@@ -79,6 +79,10 @@ + (void) endBackgroundFocusTask {
 
 + (void)onFocus:(BOOL)toBackground {
 
+    // return if the user has not granted privacy permissions
+    if ([OneSignal requiresUserPrivacyConsent])
+        return;
+    
     // Prevent the onFocus to be called twice when app being terminated
     //    - Both WillResignActive and willTerminate
     if (lastOnFocusWasToBackground == toBackground)