Support service specific configs appearing in the general section of a profile file

### Describe the bug

The Rust SDK current does not support configuring following variables in a profile file
- `s3_use_arn_region`
- `s3_disable_multiregion_access_points`
- `s3_disable_express_session_auth`

### Expected Behavior

If a customer puts the variable `s3_use_arn_region` in the AWS shared configuration file (by default in ~/.aws/config).
```
[default]
s3_use_arn_region = true
```
and create an S3 client like so
```
let shared_config = aws_config::from_env()
.region(aws_sdk_s3::config::Region::new("us-west-2"))
.load()
.await;
let client = aws_sdk_s3::Client::new(&shared_config);
```
`client` should use the ARN region instead.

### Current Behavior

The current behavior has no effect on the above `client` even if the config variable is specified in a profile file. The same goes for the other variables.

### Reproduction Steps

Described above.

### Possible Solution

_No response_

### Additional Information/Context

_No response_

### Version

```text
The latest release from https://github.com/awslabs/aws-sdk-rust/releases/tag/release-2024-02-20
```

### Environment details (OS name and version, etc.)

Any

### Logs

_No response_