DLPX-86539 CIS: postgres user account settings

PR URL: https://www.github.com/delphix/delphix-platform/pull/499

debian/postinst

@@ -75,6 +75,7 @@ configure)
 			--shell /bin/bash --ingroup postgres \
 			--gecos "PostgreSQL administrator" --uid 65437 \
 			--disabled-password postgres
+		chmod 0750 /var/lib/postgresql
 	elif [[ $(id -u postgres) -ne 65437 ]]; then
 		echo "ERROR: postgres id $(id -u postgres) != 65437" >&2
 		exit 1