Convert loop labels to strings

Since ansible-core 2.15 it's a requirement to have loop
labels as strings. In order to remain code readable, we move
definition of label to vars and convert them to json string for
output.

Change-Id: I453d2db4eeefb78735db54cf9e6fa8fa5f89b069

tasks/main_certs.yml

@@ -56,7 +56,9 @@
   loop: "{{ _cert_slurp.results }}"
   loop_control:
     loop_var: install
-    label:
+    label: "{{ loop_label | to_json }}"
+  vars:
+    loop_label:
       path: "{{ install.item.dest | dirname }}"
       state: directory
       mode: '0755'
@@ -71,7 +73,9 @@
   loop: "{{ _cert_slurp.results }}"
   loop_control:
     loop_var: install
-    label:
+    label: "{{ loop_label | to_json }}"
+  vars:
+    loop_label:
       dest: "{{ install.item.dest }}"
       owner: "{{ install.item.owner | default(omit) }}"
       group: "{{ install.item.group | default('omit') }}"

tasks/standalone/install_ca.yml

@@ -29,7 +29,9 @@
   register: ca_copy
   loop: "{{ _ca_slurp.results | default([]) }}"
   loop_control:
-    label:
+    label: "{{ loop_label | to_json }}"
+  vars:
+    loop_label:
       dest: "{{ pki_trust_store_location[ansible_facts['pkg_mgr']] }}/{{ item.item.filename | default(item.item.name ~ '.crt') }}"
   when: item.skipped is not defined
   ignore_errors: "{{ ansible_check_mode }}"