Explicitly use mysql collection

Since we've switched to ansible 2.10 we should explicitly use modules
provided by mysql collection.

Change-Id: Ic0e96e219792638b24a8e62517d98e21c3150f46

tasks/galera_server_setup.yml

@@ -14,7 +14,7 @@
 # limitations under the License.
 
 - name: Create galera users
-  mysql_user:
+  community.mysql.mysql_user:
     name: "{{ item.name }}"
     host: "{{ item.host }}"
     password: "{{ item.password }}"

tests/test-galera-server-functional.yml

@@ -91,7 +91,7 @@
           - "'10.1.0.3' in wsrep_incoming_addresses.stdout"
           - "'10.1.0.4' in wsrep_incoming_addresses.stdout"
     - name: Create DB for service on 10.1.0.2
-      mysql_db:
+      community.mysql.mysql_db:
         login_user: "{{ galera_root_user }}"
         login_password: "{{ galera_root_password }}"
         login_host: "10.1.0.2"
@@ -101,7 +101,7 @@
       tags:
         - skip_ansible_lint
     - name: Grant access to the DB on 10.1.0.3
-      mysql_user:
+      community.mysql.mysql_user:
         login_user: "{{ galera_root_user }}"
         login_password: "{{ galera_root_password }}"
         login_host: "10.1.0.3"