Mount vip-config directly in wp

[pschoffer]

Description

We load vip-config.php currently from /wp/wp-content/vip-config/vip-config.php however in live environments the vip-config folders is mapped directly to /wp/vip-config (not under wp-content).

We should migrate the location to more closely match the prod environment. That way we can support other files too such as client-sunrise.php which is loaded from /wp/vip-config/client-sunrise.php

This is the second part of the change where we change mount location

This should only be merged AFTER Automattic/vip-container-images#516

Steps to Test

1. Create new dev-env
2. Attach shell to php contianer and see that vip-config is loaded under /wp/vip-config and everything still works.

[rinatkhaziev]

@pschoffer What would happen with the existing environments?

[pschoffer]

Hmm I did test it before @rinatkhaziev but now I looked more into it and I found a scenario that breaks it a bit. I dropped the details in slack, but in essance if existing environment updates after this change and starts to mount vip-config to new location it might get ignored. Because we only update wp-config-defaults.php if wp-config.php doenst exist

[pschoffer]

I think we should do this - https://github.com/Automattic/vip-container-images/pull/519/files that way update won't break existing environments after this change.

[rbcorrales]

@rinatkhaziev Is there anything we can do to move this PR forward? It seems that the work required on the vip-container-images repo was already handled. Let me know if there's anything I can do to help.