### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

In version 1.4.0 OpenSearch is returning invalid responses when specifying gzip encoding. This was working in 1.3.1. The proxied response is not gzip encoded even though the content-encoding response header says its gzip. Reproduction steps show the differences between the output directly from OpenSearch vs the proxied result.

### Expected Behavior

Returning properly encoded responses.

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

```
version: "3.9"

services:
  opensearch:
    container_name: opensearch
    image: opensearchproject/opensearch:2.3.0
    environment:
      - node.name=opensearch
      - cluster.name=opensearch-docker-cluster
      - discovery.type=single-node
      - bootstrap.memory_lock=true
      - "OPENSEARCH_JAVA_OPTS=-Xms512m -Xmx512m"
      - "DISABLE_SECURITY_PLUGIN=true"
    ports:
      - "9200:9200"
    ulimits:
      memlock:
        soft: -1
        hard: -1
    volumes:
      - data01:/usr/share/opensearch/data

  localstack:
    container_name: "${LOCALSTACK_DOCKER_NAME-localstack_main}"
    image: localstack/localstack
    ports:
      - "4566:4566"
    depends_on:
      - opensearch
    environment:
      - OPENSEARCH_CUSTOM_BACKEND=http://opensearch:9200
      - DEBUG=${DEBUG- }
      - PERSISTENCE=${PERSISTENCE- }
      - DOCKER_HOST=unix:///var/run/docker.sock
    volumes:
      - "${LOCALSTACK_VOLUME_DIR:-./volume}:/var/lib/localstack"
      - "/var/run/docker.sock:/var/run/docker.sock"

volumes:
  data01:
    driver: local
```

1. Run docker compose
```sh
docker-compose up -d
```

2. Create the OpenSearch domain:
```
awslocal opensearch create-domain --domain-name my-domain
```

3. Test - Notice content length and output
```
curl -v -X GET my-domain.us-east-1.opensearch.localhost.localstack.cloud:4566/  -H 'Accept-Encoding: gzip' --output -
curl -v -X GET localhost:9200/ -H 'Accept-Encoding: gzip' --output -
```


### Environment

```markdown
- OS:
- LocalStack: latest 1.4.0
```


### Anything else?

_No response_
"OpenSearch_1.1",
                    "OpenSearch_1.2",
                    "OpenSearch_1.3",
                ],
            },
            {
                "SourceVersion": "Elasticsearch_7.9",
                "TargetVersions": [
                    "Elasticsearch_7.10",
                    "OpenSearch_1.0",
                    "OpenSearch_1.1",
                    "OpenSearch_1.2",
                    "OpenSearch_1.3",
                ],
            },
            {
                "SourceVersion": "Elasticsearch_7.8",
                "TargetVersions": [
                    "Elasticsearch_7.9",
                    "Elasticsearch_7.10",
                    "OpenSearch_1.0",
                    "OpenSearch_1.1",
                    "OpenSearch_1.2",
                    "OpenSearch_1.3",
                ],
            },
            {
                "SourceVersion": "Elasticsearch_7.7",
                "TargetVersions": [
                    "Elasticsearch_7.8",