When a subscription is created using cloudformation:
```
"ProfileChangedSubscription": {
      "Type": "AWS::SNS::Subscription",
      "Properties": {
        "Endpoint": {
          "Fn::GetAtt": [
            "ProfileChangedQueue",
            "Arn"
          ]
        },
        "Protocol": "sqs",
        "FilterPolicy": {
          "eventType": [
            "created"
          ]
        },
        "TopicArn": {
          "Fn::ImportValue": {
            "Fn::Sub": "${ProfilesProfilePublishStack}-ProfileChangedTopic"
          }
        }
      }
    }
```

The specified subscription filter policy is not created. When I run `get-subscription-attributes`, I get information about non-existing filter policy:

```
{
    "Attributes": {
        "TopicArn": "arn:aws:sns:us-east-1:000000000000:profile-changed-topic",
        "Endpoint": "arn:aws:sqs:us-east-1:000000000000:profile-changed-queue",
        "Protocol": "sqs",
        "SubscriptionArn": "arn:aws:sns:us-east-1:000000000000:profile-changed-topic:936a58be-525b-4228-bfdb-c4b2f6048e8c",
        "FilterPolicy": "None"
    }
}
```
import os
import json
import unittest
from localstack.constants import TEST_AWS_ACCOUNT_ID
from localstack.utils.aws import aws_stack
from localstack.utils.common import load_file, retry, short_uid, to_str
from localstack.utils.cloudformation import template_deployer
from botocore.exceptions import ClientError
from botocore.parsers import ResponseParserError
THIS_FOLDER = os.path.dirname(os.path.realpath(__file__))
TEST_TEMPLATE_1 = os.path.join(THIS_FOLDER, 'templates', 'template1.yaml')
TEST_TEMPLATE_2 = os.path.join(THIS_FOLDER, 'templates', 'template2.yaml')
TEST_TEMPLATE_3 = """
AWSTemplateFormatVersion: 2010-09-09
Resources:
  S3Setup:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: test-%s
""" % short_uid()
TEST_TEMPLATE_4 = """
AWSTemplateFormatVersion: 2010-09-09
Transform: AWS::Serverless-2016-10-31
Parameters:
  LambdaRuntime:
    Type: String
    Default: python3.6
Resources: