update template name && add buffer_pool_instances into template

tasks/configure.yml

@@ -2,7 +2,7 @@
 - name: percona | configure Percona Server
   template:
     src: my.cnf.j2
-    dest: /etc/mysql/conf.d/01-ansible.cnf
+    dest: /etc/mysql/conf.d/01-override.cnf
     mode: '0644'
   notify: Restart Percona Server
 
@@ -28,4 +28,4 @@
     plugin_auth_string: "{{ percona_root_password }}"
     salt: "{{ percona_caching_sha2_password_salt }}"
     login_unix_socket: /var/run/mysqld/mysqld.sock
-  ignore_errors: true  # In case password is already set and socket auth is disabled
+  ignore_errors: true  # In case password is already set and socket auth is disabled