Unsupported checksum algorithm: md5

### Describe the bug

It appears that, with the new checksum algorithms that have been introduced to the S3 APIs (SHA512, MD5, XXHASH64, XXHASH3, XXHASH128), the cli binary does not correctly identify MD5. Doing a call with a parameter like --checksum-algorithm MD5 will result in the error: Unsupported checksum algorithm: md5

Theoretically this should be true for any s3 call with the checksum parameter.

### Regression Issue

- [ ] Select this option if this issue appears to be a regression.

### Expected Behavior

AWS CLI creates proper checksum header for appropriate actions and posts correctly. Does not refuse md5 checksum requests.

### Current Behavior

Unsupported checksum algorithm: md5

### Reproduction Steps

aws s3api put-bucket-policy --bucket --policy --checksum-algorithm MD5

### Possible Solution

Is this on the roadmap but not implemented yet? It's currently live in the docs: https://docs.aws.amazon.com/cli/latest/reference/s3api/put-bucket-policy.html

### Additional Information/Context

_No response_

### CLI version used

2.34.45

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

Ubuntu 22.04