Operator support with AWS Role for S3 backup/restore

Request
Operator support of AWS roles in addition to AWS credentials, safer and easier to maintain.
 
Background
In the operator, you can perform S3 backup,

apiVersion: v1

 kind: Secret

 metadata:

 name: s3-secret

 type: Opaque

 data:

 region: aGV5IG1h...

 access-key-id: bXVzaHJvb20ga2l...

 secret-access-key: cm9zY29lJ3Mgd2V0IHN...

kind: CouchbaseCluster

 spec:

 backup:

 managed: true

 image: couchbase/operator-backup:6.6.0

 serviceAccountName: couchbase-backup

 s3Secret: s3-secret

You have to use the AWS credentials in the backup.

Usually, with AWS it is better to specify a role.

from the cbbackupmgr docs:

When running cbbackupmgr in an AWS instance, it may use the EC2 instance metadata to get credentials. This is disabled by default, however, may be enable by setting the CB_AWS_ENABLE_EC2_METADATA environment variable to true.
For example, if we wanted to use cbbackupmgr with the EC2 instance metadata we would: 1) Create a role with a policy which allows S3 data manipulation (e.g. S3 Full Admin) 2) Attach that role to the instance 3) Run export CB_AWS_ENABLE_EC2_METADATA=true to enable fetching EC2 instance metadata 4) Run cbbackupmgr as described elsewhere in this tutorial

https://docs.couchbase.com/server/current/backup-restore/cbbackupmgr-cloud.html#aws-3