201-aci-wordpress - Can't create test file

--------------------MESSAGE FROM ADMIN, DELETE BEFORE SUBMITTING----------------------

Sorry to hear you had a bad experience with one of the templates :worried: But, in case you're just asking a question, we're happy to help. You can also check if the question might already have been asked here https://github.com/Azure/azure-quickstart-templates/issues?utf8=%E2%9C%93&q=is%3Aissue

We've created an outline of recommended sections to fill out that will help make this Pull Request awesome!

--------------------MESSAGE FROM ADMIN, DELETE BEFORE SUBMITTING----------------------

[201-aci-wordpress](https://github.com/Azure/azure-quickstart-templates/tree/master/201-aci-wordpress)

### Issue Details

The MySQL container in the wordpress sample never starts up. It's unable to create any files on the Azure File Share it creates:

```
018-11-04 06:35:20 0 [Note] /usr/sbin/mysqld (mysqld 5.6.42) starting as process 32 ...
2018-11-04 06:35:20 32 [Warning] Can't create test file /var/lib/mysql/wk-caas-b8220443b10445bfa3acdf01f573b903-96adbd771f8241fcebd34e.lower-test
2018-11-04 06:35:20 32 [Warning] Can't create test file /var/lib/mysql/wk-caas-b8220443b10445bfa3acdf01f573b903-96adbd771f8241fcebd34e.lower-test
/usr/sbin/mysqld: Can't change dir to '/var/lib/mysql/' (Errcode: 13 - Permission denied)
2018-11-04 06:35:20 32 [ERROR] Aborting

2018-11-04 06:35:20 32 [Note] Binlog end
2018-11-04 06:35:20 32 [Note] /usr/sbin/mysqld: Shutdown complete
```

Note the `Can't create test file ` and `Can't change dir to '/var/lib/mysql/' (Errcode: 13 - Permission denied)` errors above. I followed the deployment steps [here](https://github.com/Azure/azure-quickstart-templates/tree/master/201-aci-wordpress#deployment-steps).

This is a very cool example and would really appreciate any help in getting over this issue. Thank you so much.

Start in the 201-aci-wordpress template directory and follow its documented deployment steps to reproduce the MySQL container failure. Inspect how the Azure File Share is mounted at /var/lib/mysql and compare the deployment output with the reported permission-denied logs. Done means the MySQL container starts successfully and can create files on the share.

Written by the indexing model from the issue text.