It is my understanding that setting an environment varialbe `TEST_AWS_ACCOUNT_ID` for localstack sets that as the AWS account for the user in localstack.

However, setting it does not actually change any ARNs. For example:

1. Start localstack using `TEST_AWS_ACCOUNT_ID="111111111111" DEBUG=1 localstack start`
2. Deploy anything with an ARN (in this example I deployed a lambda)
3. Check the ARN. Example output for lambda:
```json
$ awslocal lambda list-functions
{
    "Functions": [
        {
            "FunctionName": "localtest-local-hello",
            "FunctionArn": "arn:aws:lambda:us-east-1:000000000000:function:localtest-local-hello",
            "Runtime": "nodejs10.x",
            "Role": "test_role",
            "Handler": "handler.hello",
            "CodeSize": 3077,
            "Description": "",
            "Timeout": 6,
            "MemorySize": 1024,
            "LastModified": "2019-11-06T06:43:53.451+0000",
            "CodeSha256": "V77gR13o90ET7+XquXBBc3Rxr1qDu1bE7S+A0Wbx5ys=",
            "Version": "$LATEST",
            "TracingConfig": {
                "Mode": "PassThrough"
            },
            "RevisionId": "3d4ed679-c1a9-4b7e-ad9e-f27e8543c5e9"
        }
    ]
}
```

ARN is still 000000000000
if isinstance(value, dict):
        keys_list = list(value.keys())
        
        if keys_list == ['Ref']:
            result = resolve_ref(stack_name, value['Ref'],
                resources, attribute='PhysicalResourceId')
            return result
        if keys_list and keys_list[0].lower() == 'fn::getatt':
            return resolve_ref(stack_name, value[keys_list[0]][0],
                resources, attribute=value[keys_list[0]][1])
        if keys_list and keys_list[0].lower() == 'fn::join':
            return value[keys_list[0]][0].join(value[keys_list[0]][1])
        if keys_list and keys_list[0].lower() == 'fn::sub':
            result = value[keys_list[0]][0]
            for key, val in value[keys_list[0]][1].items():
                val = resolve_refs_recursively(stack_name, val, resources)
                result = result.replace('${%s}' % key, val)
            return result
        else:
            for key, val in iteritems(value):
                value[key] = resolve_refs_recursively(stack_name, val, resources)
    if isinstance(value, list):
        for i in range(0, len(value)):
            value[i] = resolve_refs_recursively(stack_name, value[i], resources)
    return value
def update_resource(resource_id, resources, stack_name):
    resource = resources[resource_id]
    resource_type = get_resource_type(resource)
    if resource_type not in UPDATEABLE_RESOURCES: