- When attempting to remove a created lambda permission with the new fix from https://github.com/localstack/localstack/issues/1260, throws up `SerializationError`

Code being called:

```
func deleteLambdaPermission(ctx context.Context, destinationLambdaARN, permissionStatementID string) (err error) {
	lambdaClient := services.LambdaClient()
	lambdaRemovePermissionInput := &lambda.RemovePermissionInput{
		FunctionName: aws.String(destinationLambdaARN),
		StatementId:  aws.String(permissionStatementID),
	}
	_, err = lambdaClient.RemovePermissionWithContext(ctx, lambdaRemovePermissionInput)

	return
}
```

Checking for error in tests shows the following

```
 Expected
        <*awserr.requestError | 0xc0004a2180>: {
            awsError: {
                code: "SerializationError",
                message: "failed to unmarshal response error",
                errs: [
                    {
                        awsError: {
                            code: "UnmarshalError",
                            message: "failed decoding error message",
                            errs: [
                                {
                                    msg: "invalid character '<' looking for beginning of value",
                                    Offset: 1,
                                },
                            ],
                        },
                        bytes: [60, 33, 68, 79, 67, 84, 89, 80, 69, 32, 72, 84, 77, 76, 32, 80, 85, 66, 76, 73, 67, 32, 34, 45, 47, 47, 87, 51, 67, 47, 47, 68, 84, 68, 32, 72, 84, 77, 76, 32, 51, 46, 50, 32, 70, 105, 110, 97, 108, 47, 47, 69, 78, 34, 62, 10, 60, 116, 105, 116, 108, 101, 62, 52, 48, 52, 32, 78, 111, 116, 32, 70, 111, 117, 110, 100, 60, 47, 116, 105, 116, 108, 101, 62, 10, 60, 104, 49, 62, 78, 111, 116, 32, 70, 111, 117, 110, 100, 60, 47, 104, 49, 62, 10, 60, 112, 62, 84, 104, 101, 32, 114, 101, 113, 117, 101, 115, 116, 101, 100, 32, 85, 82, 76, 32, 119, 97, 115, 32, 110, 111, 116, 32, 102, 111, 117, 110, 100, 32, 111, 110, 32, 116, 104, 101, 32, 115, 101, 114, 118, 101, 114, 46, 32, 73, 102, 32, 121, 111, 117, 32, 101, 110, 116, 101, 114, 101, 100, 32, 116, 104, 101, 32, 85, 82, 76, 32, 109, 97, 110, 117, 97, 108, 108, 121, 32, 112, 108, 101, 97, 115, 101, 32, 99, 104, 101, 99, 107, 32, 121, 111, 117, 114, 32, 115, 112, 101, 108, 108, 105, 110, 103, 32, 97, 110, 100, 32, 116, 114, 121, 32, 97, 103, 97, 105, 110, 46, 60, 47, 112, 62, 10],
                    },
                ],
            },
            statusCode: 404,
            requestID: "",
            bytes: nil,
        }
    to be nil
```
short_uid, load_file, to_str, mkdir, download, run_safe, get_free_tcp_port, get_service_protocol)
from localstack.services.infra import start_proxy
from localstack.services.awslambda import lambda_api, lambda_executors
from localstack.services.generic_proxy import ProxyListener
from localstack.services.awslambda.lambda_api import (
    LAMBDA_RUNTIME_DOTNETCORE2, LAMBDA_RUNTIME_RUBY25, LAMBDA_RUNTIME_PYTHON27,
    use_docker, LAMBDA_RUNTIME_PYTHON36, LAMBDA_RUNTIME_JAVA8,
    LAMBDA_RUNTIME_NODEJS810, LAMBDA_RUNTIME_CUSTOM_RUNTIME
)
THIS_FOLDER = os.path.dirname(os.path.realpath(__file__))
TEST_LAMBDA_PYTHON = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_integration.py')
TEST_LAMBDA_PYTHON3 = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_python3.py')
TEST_LAMBDA_NODEJS = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_integration.js')
TEST_LAMBDA_RUBY = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_integration.rb')
TEST_LAMBDA_DOTNETCORE2 = os.path.join(THIS_FOLDER, 'lambdas', 'dotnetcore2', 'dotnetcore2.zip')
TEST_LAMBDA_CUSTOM_RUNTIME = os.path.join(THIS_FOLDER, 'lambdas', 'custom-runtime')
TEST_LAMBDA_JAVA = os.path.join(LOCALSTACK_ROOT_FOLDER, 'localstack', 'infra', 'localstack-utils-tests.jar')
TEST_LAMBDA_ENV = os.path.join(THIS_FOLDER, 'lambdas', 'lambda_environment.py')
TEST_LAMBDA_NAME_PY = 'test_lambda_py'
TEST_LAMBDA_NAME_PY3 = 'test_lambda_py3'
TEST_LAMBDA_NAME_JS = 'test_lambda_js'
TEST_LAMBDA_NAME_RUBY = 'test_lambda_ruby'
TEST_LAMBDA_NAME_DOTNETCORE2 = 'test_lambda_dotnetcore2'
TEST_LAMBDA_NAME_CUSTOM_RUNTIME = 'test_lambda_custom_runtime'
TEST_LAMBDA_NAME_JAVA = 'test_lambda_java'
TEST_LAMBDA_NAME_JAVA_STREAM = 'test_lambda_java_stream'
TEST_LAMBDA_NAME_JAVA_SERIALIZABLE = 'test_lambda_java_serializable'
TEST_LAMBDA_NAME_ENV = 'test_lambda_env'
MAVEN_BASE_URL = 'https://repo.maven.apache.org/maven2'
TEST_LAMBDA_JAR_URL = ('{url}/cloud/localstack/{name}/{version}/{name}-{version}-tests.jar').format(