Creates a new DB Parameter Group.
A DB Parameter Group is initially created with the default parameters for the database engine used by
the DB Instance. To provide custom values for any of the parameters, you must modify the group after
creating it using ModifyDBParameterGroup. Once you've created a DB Parameter Group, you need to
associate it with your DB Instance using ModifyDBInstance. When you associate a new DB Parameter
Group with a running DB Instance, you need to reboot the DB Instance for the new DB Parameter Group
and associated settings to take effect.