fix: EventArc permissions in Dockerfile

Author: bshaffer

eventarc/generic/Dockerfile

@@ -40,6 +40,9 @@ RUN set -ex; \
 WORKDIR /var/www/html
 COPY . ./
 
+# Ensure the webserver has permissions to execute index.php
+RUN chown -R www-data:www-data /var/www/html
+
 # Use the PORT environment variable in Apache configuration files.
 # https://cloud.google.com/run/docs/reference/container-contract#port
 RUN sed -i 's/80/${PORT}/g' /etc/apache2/sites-available/000-default.conf /etc/apache2/ports.conf