(CDPE-6220) Fix variable references in run.pp

Currently, CD4PE is using this module as part of the version 5
installation. When we use docker::run, we're getting warnings like this
in the customer-facing terminal output:

Unknown variable: 'docker::docker_group'. (file: /Users/eric.putnam/ws/cd4pe/PipelinesInfra/deploy/envs/cdpe6633/.modules/docker/manifests/run.pp, line: 268, column: 19)
Unknown variable: 'docker::service_name'. (file: /Users/eric.putnam/ws/cd4pe/PipelinesInfra/deploy/envs/cdpe6633/.modules/docker/manifests/run.pp, line: 267, column: 19)

This doesn't make for a very good customer experience. Since these vars
are in docker::params, I added "::params" to the two lines where
docker_group and service_name are assigned and that seemed to take care
of the warnings. Please correct me if I'm wrong about this change, our
main goal is to get rid of these warnings.

manifests/run.pp

@@ -264,8 +264,8 @@
     $docker_command = $docker::params::docker_command
   }
 
-  $service_name = $docker::service_name
-  $docker_group = $docker::docker_group
+  $service_name = $docker::params::service_name
+  $docker_group = $docker::params::docker_group
 
   if $restart {
     assert_type(Pattern[/^(no|always|unless-stopped|on-failure)|^on-failure:[\d]+$/], $restart)