Add a common ServiceTemplateAutomation parent class

Add a common parent class that Awx/AnsibleTower/TerraformEnterprise can
inherit from.

Author: agrare

app/models/service_template_ansible_tower.rb

@@ -1,6 +1,5 @@
-class ServiceTemplateAnsibleTower < ServiceTemplate
+class ServiceTemplateAnsibleTower < ServiceTemplateAutomation
   include ServiceConfigurationMixin
-  include ServiceTemplateAutomationMixin
 
   before_update :remove_invalid_resource
 
@@ -31,11 +30,6 @@ def remove_invalid_resource
     end
   end
 
-  def create_subtasks(_parent_service_task, _parent_service)
-    # no sub task is needed for this service
-    []
-  end
-
   def self.default_provisioning_entry_point(_service_type)
     '/AutomationManagement/AnsibleTower/Service/Provisioning/StateMachines/Provision/CatalogItemInitialization'
   end

app/models/service_template_automation.rb

@@ -0,0 +1,16 @@
+class ServiceTemplateAutomation < ServiceTemplate
+  include ServiceTemplateAutomationMixin
+
+  def create_subtasks(_parent_service_task, _parent_service)
+    if generic?
+      # no sub task is needed for this service
+      []
+    else
+      super
+    end
+  end
+
+  def generic?
+    prov_type.start_with?("generic_")
+  end
+end

app/models/service_template_awx.rb

@@ -1,6 +1,5 @@
-class ServiceTemplateAwx < ServiceTemplate
+class ServiceTemplateAwx < ServiceTemplateAutomation
   include ServiceConfigurationMixin
-  include ServiceTemplateAutomationMixin
 
   before_update :remove_invalid_resource
 
@@ -31,11 +30,6 @@ def remove_invalid_resource
     end
   end
 
-  def create_subtasks(_parent_service_task, _parent_service)
-    # no sub task is needed for this service
-    []
-  end
-
   def self.default_provisioning_entry_point(_service_type)
     '/AutomationManagement/AnsibleTower/Service/Provisioning/StateMachines/Provision/CatalogItemInitialization'
   end