Add 'load' boolean for services.

Some services, such as socket activated ones with '@' naming cannot be
loaded.

Change-Id: I7d95378f393c8b8cc729cc9b3a30dfe4208393b2

defaults/main.yml

@@ -121,6 +121,7 @@ systemd_environment: {}
 #                              will place only overrides for the existing service.
 #  `systemd_run_dir` -- (optional) Run directory that will be used for service runtime. Service slice or name is added to the path
 #  `systemd_lock_dir` -- (optional) Lock directory that will be used for service runtime. Service slice or name is added to the path
+#  `load` -- (optional) Boolean to set if the service is loaded. Socket activated services with '@' may not need to be loaded.
 
 # Under the service dictionary the "sockets" key can be added, which may contain list of the sockets
 #  for the given service_name. Each socket in the lsit may have following structure:

tasks/main.yml

@@ -146,6 +146,8 @@
     enabled: "{{ item.enabled | default(systemd_service_enabled) }}"
     state: "{{ (item.timer is defined) | ternary(omit, (item.state | default(omit))) }}"
   with_items: "{{ systemd_services }}"
+  when:
+    - item.load | default(True)
   tags:
     - systemd-service