Change pulp users group from users to pulp

fixes #7173
https://pulp.plan.io/issues/7173

CHANGES/7173.bugfix

@@ -0,0 +1 @@
+Changed pulp users main group from 'users' to '{{ pulp_group }}'.

molecule/scenario_resources/tests/test_default.rb

@@ -2,6 +2,11 @@
   its('owner') { should eq 'root' }
 end
 
+describe directory('/var/lib/pulp/') do
+  its('owner') { should eq 'pulp' }
+  its('group') { should eq 'pulp' }
+end
+
 ['pulpcore-api','pulpcore-content','pulpcore-resource-manager', 'pulpcore-worker@1', 'pulpcore-worker@2'].each do |pservice|
   describe service(pservice) do
     it { should be_running }

roles/pulp_common/tasks/install.yml

@@ -43,6 +43,7 @@
         shell: '{{ result.stdout.strip() }}'
         home: '{{ pulp_user_home }}'
         system: true
+        group: '{{ pulp_group }}'
         groups:
           - '{{ pulp_group }}'
         append: true
@@ -132,6 +133,14 @@
 
       when: pulp_user_home_stat.stat.pw_name == "apache"
 
+    - name: Set group on all files in '{{ pulp_user_home }}'
+      file:
+        path: '{{ pulp_user_home }}'
+        state: directory
+        group: '{{ pulp_group }}'
+        recurse: true
+        follow: false
+
     - name: Install packages needed for source install
       package:
         name: