[bitnami/apache] Fix htdocs with readOnlyRootFilesystem

[migruiz4]

Description of the change

Fixes an issue with apache, where deployment will fail when htdocs are mounted.

apache 09:12:49.11 INFO  ==> ** Starting Apache setup **
apache 09:12:49.22 INFO  ==> Mounting application files from '/app'
rm: cannot remove '/opt/bitnami/apache/htdocs/index.html': Read-only file system

This issue is caused by this section of the image logic:

if ! is_dir_empty "/app"; then
    info "Mounting application files from '/app'"
    rm -rf "$APACHE_HTDOCS_DIR"
    ln -sf "/app" "$APACHE_HTDOCS_DIR"
fi

Mounting the htdocs at /app will attempt to remove /opt/bitnami/apache/htdocs, causing the above permission error.

Possible drawbacks

This PR mounts the htdocs directly at /opt/bitnami/apache/htdocs, causing the /app folder to remain empty from now on.

Applicable issues

• fixes [bitnami/apache] htdocsConfigMap is incompatible with containerSecurityContext #25669

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)