Make sure dump_vars_log_dir dir exists

https://review.opendev.org/752309 made changes to dump_vars role
and make loose become, but it leads to permission denied while
creating dump_vars_log_dir. Setting proper permission and
enabling become fixes the issue.

Closes-Bug: #1896439

Change-Id: I4c6a0333cc2fc8cf4d042740baafc28b2e08a5ee
Signed-off-by: Chandan Kumar (raukadah) <chkumar@redhat.com>

roles/dump_vars/tasks/main.yml

@@ -1,6 +1,10 @@
 ---
 - name: Prepare directory with extra logs
-  file: dest={{ dump_vars_log_dir }} state=directory
+  become: true
+  file:
+    dest: "{{ dump_vars_log_dir }}"
+    state: directory
+    mode: 0777
 
 - name: generate dump_variables_vars script
   template: