Firebase multiple file uploading issue with Swift 3 - swift

Question

So I am fairly new to swift and firebase, however I have come to realize that using firebase to sync data has created a particular issue for me. I have a very simple application that basically allows users to upload multiple images onto the firebase storage.
What is happening in my code now is that once the very first image that was uploaded is done, the view segues to the next view controller. What I want to do is to only have it segue when ALL of the images are uploaded not just one
What I have attempted to do is create a List of Floats and for every Image that the user intends to upload, I will only keep track of the very last Image uploaded. However, I have to believe that there is another way of doing this. Furthermore my solution does not seem to be working correctly.
func observeUploadProgress(for job: Job) {
let imageName = UUID().uuidString
let storageRef = FIRStorage.storage().reference().child("\(imageName).png")
let uploadData = UIImagePNGRepresentation(job.beforeImage!)
let uploadTask = storageRef.put(uploadData!, metadata: nil, completion: { (metadata, error) in
if error != nil {
print(error)
return
}
job.beforeImageUrl = (metadata?.downloadURL()?.absoluteString)!
self.uploadingImagesToFirebase = false
if (self.arrayProgressList[self.arrayProgressList.count - 1] >= 1.0) {
self.alertController?.dismiss(animated: true, completion: nil)
self.performSegue(withIdentifier: "unwindFromCustomerDetailsSegue", sender: self)
}
})
self.arrayProgressList.append(0.0)
let curr_index = self.arrayProgressList.count - 1
uploadTask.observe(.progress) { (snapshot) in
guard let progress = snapshot.progress else { return }
self.uploadingImagesToFirebase = true
self.arrayProgressList[curr_index] = Float(progress.fractionCompleted)
self.progressView?.progress = self.arrayProgressList[self.arrayProgressList.count - 1]
}
}