Added account id to bucket name to ensure uniqueness

[nealbrown]

Using the default resource prefix of aws-cis yields a bucket name of aws-cis-audit-logs which appears to already exist.

Insert the account id into the bucket name to yield a unique name.

Original error, ideally the AWS API would give a better response for an existing bucket but I see the security issue there:
Error: creating Amazon S3 (Simple Storage) Bucket (aws-cis-audit-logs): AuthorizationHeaderMalformed: The authorization header is malformed; the region 'us-east-1' is wrong; expecting 'eu-central-1' │ status code: 400, request id: AENNHNACK4Z82XND, host id: +5V93mvxTjXkRzWtI34PHJj5alivNUxyzFloJMKQAl2CCmDFdVwkP1M4qYDYJIGl3q3c2bhB8tw= │ │ with aws_s3_bucket.audit[0], │ on s3.tf line 101, in resource "aws_s3_bucket" "audit": │ 101: resource "aws_s3_bucket" "audit" { │ ╵