Creating an existing bucket owned by you

[jonaustin09]

Describe the bug
When a user tries to create an already existing bucket owned by him, the gateway should return BucketAlreadyOwnedByYou error instead of BucketAlreadyExists

To Reproduce
Run bucket creation command twice

aws --endpoint-url http://localhost:7070 s3api create-bucket --bucket my-bucket
aws --endpoint-url http://localhost:7070 s3api create-bucket --bucket my-bucket

Expected behavior
The gateway should return BucketAlreadyOwnedByYou error