[Bug] - CompleteMultipartUpload lower limit of uploading parts size

[0x180]

Describe the bug
When initiating a multipart upload, all uploaded parts should have the same size (except for the last part) and must be between 5 MiB and 5 GiB. If more than two parts are uploaded and any part is smaller than 5 MiB, the CompleteMultipartUpload operation should fail.

To Reproduce

aws s3api create-bucket --bucket test

aws s3api create-multipart-upload --bucket test --key obj

// file_1 should be smaller than 5Mib
aws s3api upload-part --bucket test --key obj --upload-id <mp_upload_id> --part-number 1 --body file_1

// file_2 should be smaller than 5Mib
aws s3api upload-part --bucket test --key obj --upload-id <mp_upload_id> --part-number 2 --body file_2

aws s3api complete-multipart-upload --bucket test --key obj --upload-id <mp_upload_id> --multipart-upload '{"Parts": [{"ETag": "<file_1_ETag>", "PartNumber": 1}, {"ETag": "file_2_ETag", "PartNumber": 2}]}'

Expected behavior
CompleteMultipartUpload should return the following error:

An error occurred (EntityTooSmall) when calling the CompleteMultipartUpload operation: Your proposed upload is smaller than the minimum allowed size