tasks: horizon_post_install: Ensure horizon dashboard directory is accessible

During the DB migration step, the horizon user needs full access to the
directory so we need to ensure that all the permissions are set
correctly before we reach that point.

Change-Id: I52933cf52b33bf81a2cee2f18665a1760760b08f

tasks/horizon_post_install.yml

@@ -13,6 +13,15 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+- name: Ensure horizon local dir is accessible by user
+  file:
+    path: "{{ horizon_lib_dir }}"
+    state: directory
+    owner: "{{ horizon_system_user_name }}"
+    group: "{{ horizon_system_group_name }}"
+    mode: "0755"
+    recurse: yes
+
 - name: Setup Horizon config(s)
   template:
     src: "{{ item.src }}"