Fix idempotency for systemd keyword

Fix #936
Signed-off-by: Sagi Shnaidman <sshnaidm@redhat.com>

plugins/module_utils/podman/podman_container_lib.py

@@ -1419,6 +1419,8 @@ class PodmanContainerDiff:
         return self._diff_generic('sysctl', '--sysctl')
 
     def diffparam_systemd(self):
+        if self.params['systemd'] is not None:
+            self.params['systemd'] = str(self.params['systemd']).lower()
         return self._diff_generic('systemd', '--systemd')
 
     def diffparam_timeout(self):

tests/integration/targets/podman_container_idempotency/tasks/idem_all.yml

@@ -549,6 +549,42 @@
     that:
       - test37 is changed
 
+- name: Run container with systemd
+  containers.podman.podman_container:
+    executable: "{{ test_executable | default('podman') }}"
+    image: "{{ idem_image }}"
+    name: idempotency
+    state: present
+    systemd: false
+
+- name: Run container with same systemd
+  containers.podman.podman_container:
+    executable: "{{ test_executable | default('podman') }}"
+    image: "{{ idem_image }}"
+    name: idempotency
+    state: present
+    systemd: false
+  register: test38
+
+- name: Check container with same systemd
+  assert:
+    that:
+      - test38 is not changed
+
+- name: Run container with different systemd
+  containers.podman.podman_container:
+    executable: "{{ test_executable | default('podman') }}"
+    image: "{{ idem_image }}"
+    name: idempotency
+    state: present
+    systemd: always
+  register: test39
+
+- name: Check container with different systemd
+  assert:
+    that:
+      - test39 is changed
+
 - name: Remove dependent test container
   containers.podman.podman_container:
     executable: "{{ test_executable | default('podman') }}"