S3ClientBuilder will not use the system configured https.proxyHost

### Describe the bug

By default, S3ClientBuilder will not use the system configured https.proxyHost. Instead it uses the system configured http.proxyHost

### Expected Behavior

S3ClientBuilder should connect through the proxy specified by https.proxyHost.

### Current Behavior

S3ClientBuilder ignores the value in https.proxyHost. If http.proxyHost is configured, it will connect through that proxy even though it is using an https connection.

### Reproduction Steps

1. Unzip s3client.zip
2. Build s3client.jar with "gradlew clean build"
3. set up environment variables:
AWS_KEY_ID=some aws access key
AWS_KEY_SECRET=some aws secret key
AWS_REGION=some aws region
4. set up https proxies
export _JAVA_OPTIONS="-Dhttps.proxyHost=SOME_PROXY_HOST -Dhttps.proxyPort=SOME_PROXY_PORT"
5. run java -DLOGGING_LEVEL_ORG_APACHE_HC=DEBUG -DSOFTWARE_AMAZON_AWSSDK=DEBUG -jar s3client.jar
6. if the proxy really is necessary, see a failure!
Exception in thread "main" software.amazon.awssdk.core.exception.SdkClientException: Unable to execute HTTP request: Connection reset
at software.amazon.awssdk.core.exception.SdkClientException$BuilderImpl.build(SdkClientException.java:111)
at software.am
[s3client.zip](https://github.com/aws/aws-sdk-java/files/11066243/s3client.zip)
azon.awssdk.core.exception.SdkClientException.create(SdkClientException.java:47)
7. in the output logs, see that NO proxy was picked up. You will NOT see "ApacheHttpClient - Configuring Proxy. Proxy Host: SOME_PROXY_HOST"
8. set up http proxies
export _JAVA_OPTIONS="-Dhttps.proxyHost=SOME_PROXY_HOST -Dhttps.proxyPort=SOME_PROXY_PORT -Dhttp.proxyHost=SOME_PROXY_HOST -Dhttp.proxyPort=SOME_PROXY_PORT"
9. run java -DLOGGING_LEVEL_ORG_APACHE_HC=DEBUG -DSOFTWARE_AMAZON_AWSSDK=DEBUG -jar s3client.jar
10. see a successful list of your s3 buckets!
11. in the output logs, see that a proxy was picked up. You will see "ApacheHttpClient - Configuring Proxy. Proxy Host: SOME_PROXY_HOST"

### Possible Solution

_No response_

### Additional Information/Context

It looks like this happens becuase software.amazon.awssdk.http.apache.ProxyConfiguration won't set a host if no endpoint was provided, and an endpoint is not provided by default. So by default, the S3Client (and I assume other aws clients) will connect using https (good), but use the http.proxyHost system setting, instead of the https.proxyHost system setting (bad).

I tried calling s3ClientBuilder.endpointOverride("https://HOST:PORT"), but S3Client continued to fail to connect. And endpointOverride looks like it is expecting an S3 URL anyway.

### AWS Java SDK version used

2.20.30

### JDK version used

OpenJDK 17.0.6

### Operating System and version

Oracle Linux 8.7