Add option to skip setting CloudWatch Log Group retention policy

[ea-mtenhoor]

efs-utils 2.4.1
Ubuntu 24.04

We are using the CloudWatch Logs integration with efs-utils, but would prefer to manage the CloudWatch Log group retention settings elsewhere in our IAC.

Currently, in efs-utils.conf there is this comment.

# Comment this config to prevent log deletion
retention_in_days = 14

However, when the retention_in_days line is commented out efs-utils still sets the log group retention to 14 days, due to a default in the code. Based on the wording of the comment, it seems to suggest that if retention_in_days is commented out, efs-utils will either skip retention policy management, or delete the policy (which sets the group to 'Never expire').

For our use case, we would prefer that commenting out retention_in_days simply skips code that would manage retention settings. However, if it is more intuitive that when retention_in_days is commented out the log group should be set to 'Never expire', an additional config setting could be added to enable or disable retention management.