Hello,
I am working with a SNS to SQS project, in it we want to use the feature `RawMessageBody` when subscribing.
By looking into the code I found that the attributes are not persisted, for example `RawMessageBody` is always set to 'false'. Elsewhere in the code the parameters seems to be correctly used and send transform the message accordingly.

I created a PR fixing this : https://github.com/localstack/localstack/pull/1234
Thank you 
{'filter': [{'numeric': ['=', 300]}]},
            {'filter': {'Type': 'Number', 'Value': 300}},
            True
        ),
        (
            'numeric = filter with no match',
            {'filter': [{'numeric': ['=', 300]}]},
            {'filter': {'Type': 'Number', 'Value': 301}},
            False
        ),
        (
            'numeric > filter with match',
            {'filter': [{'numeric': ['>', 300]}]},
            {'filter': {'Type': 'Number', 'Value': 301}},
            True
        ),
        (
            'numeric > filter with no match',
            {'filter': [{'numeric': ['>', 300]}]},
            {'filter': {'Type': 'Number', 'Value': 300}},
            False
        ),
        (
            'numeric < filter with match',
            {'filter': [{'numeric': ['<', 300]}]},
            {'filter': {'Type': 'Number', 'Value': 299}},
            True
        ),
        (
            'numeric < filter with no match',