Using customConfigs wipes out defaults

I've been dealing with an issue where I'm trying to add LDAP configuration to xwiki.cfg, but adding anything to customConfigs makes it so only these items will end up in "/usr/local/xwiki/data/xwiki.cfg", which results in issues mentioned here: https://forum.xwiki.org/t/xwiki-helm-offline/15648/7

The workaround is to add all the default values to customConfigs, which sort of defeats the purpose of why the chart deletes these files in the persistent storage.

It looks like this functionality would have worked at one point, but the Docker image no longer copies the files from the WEB-INF directory to the persistent directory as per https://forum.xwiki.org/t/improve-xwiki-docker-image-configuration-strategy/15008.

There's a few options on how this can be handled:

• Copy the files from WEB-INF to the persistent storage after calling first_start
• Change the generation of initialization-secrets.yaml to point to "/usr/local/tomcat/webapps/$CONTEXT_PATH/" instead of "/usr/local/xwiki/data/" for all files

For the first option, it may also be a good idea to change the Docker image to have configure call restoreConfigurationFile instead of saveConfigurationFile since they now both do the same thing and then change saveConfigurationFile to copy from WEB-INF to the persistent directory so initialization-secrets can call that instead of needing to know the location of the files (in case they happen to change someday).

It may also be nice to add a Chart value to exclude the file deletion at the start of initialization-secrets so users can choose to just keep what they have.