Cherry pick sdk-274-push-ios13

Author: nzagorchev

Example/Tests/Classes/LPPushNotificationsHandlerTest.m

@@ -105,7 +105,20 @@ - (void) test_receive_notification
 
     //test when UNUserNotificationCenter.currentNotificationCenter.delegate is nil
     UNUserNotificationCenter.currentNotificationCenter.delegate = nil;
-    [handler didReceiveRemoteNotification:userInfo
+    
+    // Requires Leanplum Start
+    // didReceiveRemoteNotification: UIApplicationState is Active -> calls handleNotification -> runs onContent on startIssued callback
+    if (!Leanplum.hasStarted){
+        XCTAssertTrue([LeanplumHelper start_production_test]);
+    }
+    
+    // Change messageId so it is not a duplicate notification
+    NSDictionary* userInfo2 = @{
+                                @"_lpm": @"messageId_2",
+                                @"_lpx": @"test_action",
+                                @"aps" : @{@"alert": @"test"}};
+    
+    [handler didReceiveRemoteNotification:userInfo2
                                withAction:@"test_action"
                    fetchCompletionHandler: ^(LeanplumUIBackgroundFetchResult result) {
                                             [applicationNotificationExpectation fulfill];

Leanplum-SDK/Classes/Notifications/Push/LPPushNotificationsHandler.m

@@ -230,6 +230,10 @@ - (void)handleNotification:(NSDictionary *)userInfo
         return;
     }
 
+    if ([self isDuplicateNotification:userInfo]) {
+        return;
+    }
+    
     void (^onContent)(void) = ^{
         if (completionHandler) {
             completionHandler(UIBackgroundFetchResultNewData);
@@ -266,11 +270,6 @@ - (void)maybePerformNotificationActions:(NSDictionary *)userInfo
                                  action:(NSString *)action
                                  active:(BOOL)active
 {
-    // Do not perform the action if the app is in background
-    if (UIApplication.sharedApplication.applicationState == UIApplicationStateBackground) {
-        return;
-    }
-
     // Don't handle duplicate notifications.
     if ([self isDuplicateNotification:userInfo]) {
         return;