Fix ansible deprecation warnings

===
[DEPRECATION WARNING]: Using tests as filters is deprecated.
Instead of using `result|search` use `result is search`. This
feature will be removed in version 2.9.
===

Change-Id: I8e856ecaeb82446785dbdcd23688bb0db0a30857

tasks/keystone_credential_create.yml

@@ -40,7 +40,7 @@
       {%   endif -%}
       {% endfor -%}
       {{ _var }}
-  when: not credential_key_list | skipped
+  when: not credential_key_list is skipped
 
 - name: Collect the existing keys from containers
   slurp:

tasks/keystone_install.yml

@@ -136,7 +136,7 @@
       state: "True"
     - name: "install_method"
       state: "{{ keystone_install_method }}"
-  when: (install_packages | changed) or
+  when: (install_packages is changed) or
         (ansible_local is not defined) or
         ('openstack_ansible' not in ansible_local) or
         ('keystone' not in ansible_local['openstack_ansible']) or