GalleryActivity.kt

private fun uploadImage(){
    if(filePath != null){
        val ref = storageReference?.child("uploads/" + UUID.randomUUID().toString())
        val uploadTask = ref?.putFile(filePath!!)

        val urlTask = uploadTask?.continueWithTask(Continuation<UploadTask.TaskSnapshot, Task<Uri>> { task ->
            if (!task.isSuccessful) {
                task.exception?.let {
                    throw it
                }
            }
            return@Continuation ref.downloadUrl
        })?.addOnCompleteListener { task ->
            if (task.isSuccessful) {
                val downloadUri = task.result
                addUploadRecordToDb(downloadUri.toString())
            } else {
                // Handle failures
            }
        }?.addOnFailureListener{

        }
    }else{
        Toast.makeText(this, "Please Upload an Image", Toast.LENGTH_SHORT).show()
    }
}